X3! It would be a vast improvement if it defaulted to the "Off" mode upon start.

The only one on your list that bothers me are the over-active pre-sense sensors which have scared the crap out of me before by slamming on the breaks unexpectedly.

My list, in order of annoyance:

1) Throttle response at low speeds is just awful
2) Gas mileage of 17mpg over the last 4000 miles driven, which when combo'd with #1 above I find offensive
3) RATTLES, RATTLES, RATTLES. Car has been back for speaker rattles, door rattles, and rattles from the hatch area. I've given up and just blast the music now, but there's just no excuse for a car of this price to constantly creak and pop. For comparison, the A3 and A6's I've gotten as loaners have been whisper quiet.
4) Not sure if it's the tire or suspension, but even in Comfort driving over potholes is a jaw shattering experience
5) Lumbar support doesn't extend as far as on A models, and isn't retained in memory so has to be adjusted every time I start the car
6) No way to permanently disable the auto stop engine nonsense
7) B&O premium system blows considering the cost. I've had 4 speakers replaced because they've gone bad, and my dealer under argument/duress had to line the doors with dynamat to get functional bass that didn't vibrate the door.
8) D mode is basically an unusable drive mode unless you think a numb gas pedal is advantageous.

Exactly this. It's not the money.

Wow, can't believe I agree with almost every single point. Not sure I agree with the rattles thing. Mines not that bad.

One of the benefits of the RS5 is it doesn't have ASS. Luckily I haven't had any issues with rattles. Thought I was but realized it was the passenger seat belt hitting the plastic. Moving the seat belt fixed the issue. The B&O system has been fine for me. I've heard better custom systems but it's more then adequate IMO. First thing I did was turn off the 3D sound.

X4!
It feels like the car has stalled, just like a few of the beater cars I had when I was young.
I ALWAYS hit the xxx button after the ignition.

I actually find D mode advantageous in city traffic. S is too touchy for me in those situations. I don't much think about turning the ASS off, or switching into/out of S anymore.

I find D mode to be good for long highway cruising. I drive ~30 miles of straight highway to and from work and just put it in D and it's not bad. I might manual downshift if I'm gonna pass someone but otherwise it's tolerable. A little better for mileage as well if you're into that. Short trips, city driving, carving up mountainous roads i leave it in S.

For me it seems like it takes 5 seconds for the car to move in D mode. And when it does move, it rockets ahead. Completely unusable in NYC traffic.

I am aware of the thread title, but just had to respond. I see that most of us have a couple of gripes, but it makes me sad to see anyone with a long list. Clearly Audi did not meet their expectations and now they are out $60+K. Of course I have a couple of gripes, always have, no matter what vehicle I have owned, but I love this car.
These comments are all in reference to my opinion, experience, or expectations and I am sensitive to what others find unacceptable, so please, no flaming.

Agree. Anywhere that the traffic is light, D is great.

Most of the time I like the auto stop start. Especially at a long light. It is very unobtrusive and restarts the vehicle before I can get my foot off the brake. If I want it to start the car sooner, I just drop it into Sport, or lighten pressure on the brake and it starts right up. Seamless and well executed. Conversely , if I do not want it to engage while in drive, I simply maintain only light pressure on the brake.

I have a coupe, and with the bass cranked up on bass heavy tracks, the rear shelf/sub rattles. Turning the bass level way down eliminates this which is unacceptable. I will be pursuing this with Audi, failing any help there I will be looking for an aftermarket fix. Aside from that, my old ears love the system.

You couldn't even count to 1, nevermind 5 seconds lol.

+1. I agree, the delay for me is very short if there at all.

I am so sorry you got a lemon, time to move on instead of having to deal with all these problems. Life is too short :)
Let me try to respond to some of these problem you have,
1. Slow throttle response, if you want to drive aggressively, you need to be in sport mode, unlike many other cars, the D mode in the S5 is mapped very conservatively.
2. Your car is not even broken in yet, hopefully mileage will improve. Sounds like you like to drive aggressively, 17 MPG is pretty good for aggressive driving.
3. If you have rattles and don't do anything about it, its your own fault. Your car is still under warranty, sometimes it takes the dealer multiple tried to fix the problem. Take the shop foreman for a test drive and show him or her where the rattles are.
4. Are you expecting not to feel any pothole in a sports car? Maybe the Mercedes S class or the Lexus LS is more appropriate for you. The S5 with adaptive suspension in comfort has one of the most comfortable ride in this class of cars.
5. My lumbar support extend pretty far out to the point where my back is arched. I guess everybody's body shape is different.
6. I used the auto start stop all the time, it has become second nature to me. BMW use to disable the ASS at the customer's request but even they have stop doing that,
7. For $800, I would say the B&O system is about average. I think you are just expecting too much.
8. I drive in D all the time, it is hardly un-useable, it just need the right driver. Again, if you are an aggressive driver, you need to be in S mode.

FYI here is how I fixed 100% of my gripes:

• I put a kicker hideaway 10" sub in the trunk (https://www.kicker.com/hideaway). Also, I reeeeaaalllly hate to admit it, but the B&O system has "broken in" and now sounds pretty good. When I first got it I couldn't stand it, it is still lacking in the mid-section, but after about 6months I definitely hear a change in performance in these speakers.
• I disabled Auto Start/Stop using ODB11
• I drive primarily in S mode, and kick it over to D when I am on the highway

Now I am 100% happy. I literally cannot think of any gripes any more.

Here are my first impressions regarding some of the common gripes. I am coming from a B8 A4 with a 2.0T and the ZF8.

- Transmission/throttle lag is less of a problem than I anticipated and the ZF8 behavior in D and S seems fairly similar to that of the B8. Actually, this incarnation seems smoother in low speed driving thus far, as the transmission in my previous car was prone to occasional jerky downshifts at low speed since it was new. Also, the higher low-end torque of the 3.0T makes the drivetrain feel slightly less dead at low RPM and higher gear. D mode seems better suited to city driving in my area, as S is certainly more fun, but overly aggressive for stop-and-go driving. I haven't pushed the car beyond 3500 RPM yet, so my opinion may change with more driving.
- The adaptive suspension is more comfortable than the fixed sport suspension in my A4. In comfort mode with 19" wheels, the ride is more comfortable than the A4 with 18" wheels and dramatically more comfortable than the A4 with 19" wheels. The ride isn't even particularly bad in Dynamic; I would rate it as somewhere between the A4 with 18" wheels and 19" wheels.
- The biggest annoyance so far is a rattle emanating from the sunroof cover. Another reason I would have preferred a sunroof delete option.

-- I drive exclusively in S mode because I find D mode a simply unusable drive mode. It's ridiculously bad at anything but cruising on the highway. When I'm talking laggy throttle response, I am talking about S mode. There's tons of threads about it already, and even the commercial car reviewers like Car and Driver mention it in their reviews. Under 40mph or so the throttle is just laggy and the car feels heavy.

-- I have 9500 miles on the car so it's broken in. I've gotten 17mpg on my last 4k miles. Personally, I wouldn't care about the MPG IF the throttle response wasn't an issue. But since the car feels way more laggy than my 2014 S4 which easily got 22mpg, I'm annoyed. I also don't drive the car hard, yet even in D mode the best I can eke out is 21mpg. That's 50/50 highway/city driving too.

-- In regards to the suspension, I'm suspecting something is wrong. It wasn't so clunky (particularly in the rear) when I first got it, now it is loud and hard when hitting potholes. The A3, A4, and A6 loaners I've had have all been far smoother rides, even in their dynamic modes.

- "expecting too much on B&O". This "premium" system is worse than my old 2005 Honda Civic. They have already replaced multiple speakers, but it turns out the problem is really the cheap plastic grilles they use which can't handle certain resonance frequencies. It's actually at the shop right now for the 3rd time as they attempt to dynamat the passenger speaker that rattles the whole door, and find the loose part that's rolling around in the door from their last attempted fix.

I actually don't consider these things something that makes the car a "lemon". However the 2 airbag lights/replacements , front dash wiring harness replacement (whole front dash went dark), engine thermostat replacement (check engine light), multiple speaker replacements, stuck radio number pad (the 1-8 on the console for the radio), and "dancing windows" (windows skipping) could probably qualify it as that. Imho, I think half my problems/rattles have been caused by them ripping apart the car to fix the broken airbags and speakers.

So in dynamic mode, how long of a delay do you get when you push the throttle until the car launch forward uncontrollably? It is like a 5 seconds delay like some others in here have suggest, or is the delay longer or shorter than 5 seconds in dynamic mode. Either way, 99% of us have no lag in dynamic mode, in fact most of us find it too touchy in the dynamic mode. Again, you have a lemon, start talking to lemon law lawyer. When I punch it in Dynamic mode, there is zero delay and the car takes off like a bat out of he11. My car does not feel heavy at all, you do realized that this is a 4000 pound car and not a 2500 pound Miata.
The B9 is suppose to be way more fuel efficient than the B8, again, you need to talk to the dealer or a good lawyer.
Your rear shocks might be leaking or your adaptive suspension electronic might not be working.
My B&O is on par with my old BMW harman kardon system, not bad for a $800 system, no blown speakers here. Sounds like your car was build on a Friday afternoon right before quitting time.

You listed about 12 things wrong with your car, all happened before 10K miles. I would say your car is a lemon. In some states, if you had a certain amount of shop visit, it qualify you for the lemon law. I would start looking into your state's lemon law.

Mine does not rattle, but I also would like the option of deleting it up front. I have no use and get no joy from them, Probably in the minority though and that's why you cannot buy a car without one today.

Sounds very simple and enticing. Can the wires to the rear shelf sub in the coupe be run directly to this unit, or is their a separate amp required?

I think I have used the sunroof twice in one year, I wish I could do a sunroof delete, save money, save weight, more headroom...............

I rarely use sunroof as well however the rattle will sound regardless if you use it or not. It's quite an annoying ticking. My guess is the extreme cold temperatures since first time i experienced it, temperatures were at -30 degrees celsius and the second time we had ice rain.

Yeah, maybe it's the cold. I live in Houston and have not experienced any rattling from the sunroof. I have my shade retracted as I tinted my sunroof and enjoy the view with the shade back. The only rattling I've experienced was the passenger seat beat hitting the plastic near the side pillar. Adjusting the seatbelt fixed that issue.

I agree with the complaints about the small gas tank. This size tank would work in a Prius, but certainly not in this car. I filled up once a week with my old car and should be able to still make it that long with the S5, but it is still surprising that Audi considered this tank sufficient.

I'm going to try driving with the sunroof cover retracted to see whether that reduces or eliminates the rattle. It isn't extremely loud or annoying anyway, but this is the gripes thread.

Gas tank is definitely smaller then I would prefer. Any "spirited" driver results in a very quick trip to the gas station.
Hopefully it helps. I didn't hear any rattling before retracting though.

My gripes after 13 months:

1) Rattles/vibration noise - Been to the dealer once about it in conjunction with scheduled maintenance, but they didn't have time to investigate the issues fully before I needed the car back. My service advisor acknowledged he heard some of the issues and I'll address this at my next service visit. Some of it sounds like it's coming from the passenger side speaker or seatbelt assembly; some sounds like it's coming from the carbon fiber trim around the center console; some seems to come from the MMI screen.
2) Faint single electronic beep every time I depress the brake pedal just before coming to a complete stop (as opposed to just slowing down). I think this has been there all along, but only noticed it recently when I didn't have music playing (I always have something playing). Will bring this up at my next service visit.
3) Every once in a while the driver's side window doesn't seal properly when I enter the car. I assume this relates to having tint, the weather/temperature, etc. and it doesn't happen enough to really annoy me.
4) The projected remaining mileage issue others have discussed above. I love having it go from 95 miles remaining to 40 after driving a couple of non-boisterous miles and parking and restarting the car.

Don't know if I have trained it or gotten used to it and learned to drive around it, but it isn't bothering me nearly as much as when I first got the car. I feel like it has gotten better though.

I'm no audiophile but I do feel like the sound lacks a bit of richness that I had in the C43. Not sure what that is but I gathered from the boards it is just not the same quality of a system.