I bought my 15 A8 L a month ago and haven't looked back. The best indication of having made the right choice was how much I enjoyed a 6 hour drive down and back from DFW to Austin the day after I got it. To use a phrase previously said it was "effortless" as if the car drove itself. Like the car you described my car is out of warranty and had just a few more miles at 69k.

Now on to answer your questions best I can...

1. How prevalent is the loss of turbo oil supply due to screen clogging and is there any warning?

• Gotta say this is news to me. Didn't crop up in my research as common issues.

2. Is the downpipe vibration in all, most or just some of the cars?

• Mine has it and I knew it going in. Going to do engine mounts and SW updates before deciding how to handle.

3. Has anyone simply caulked the windshield to trim interface for the seemingly common leak?

• Thought I had this when it was raining heavily lately and had a mildew smell but turned out to be sunroof. Did some good cleaning and seems to have gone away. No actual wetness or moisture around the windshield/headliner.

4. Is replacing the engine mounts that common? Assuming normal driving at what mileage? Should one avoid tunes on these cars that increase the loading on the mounts?

• Back to the engine mounts, I've had the dealer and two independent Audi shops verify this as a key issue to address and will be doing it this week.

5. As a buyer at what mileage would you go “eh” I’ll keep looking. Is this car a long distance runner or more half marathon? What type of mileage are you TDI guys getting?

• For me it was the best condition car I could find in my price range with the options/colors I wanted. For piece of mind I had an inspection done and by multiple accounts the car would have been CPO except for mileage (although like most dealerships they were clueless about the 1k/3k vibration issue). As for a deposit to do the inspection I call BS. I told the place I eventually bought from that I would need the car for a 1/2 day to inspect and they were totally cool.

6. Do all season tires perform well? I see a lot of cars with summer performance tires.

• Rarely see snow in N Texas so not an issue for me.

Indeed it is. Just another reason to pass.

Agreed

Picked up a 2016 A8L 4.0 yesterday with an ULEV II mod. The car has about 36,000 miles and is immaculate inside. Seems to have everything but maybe the Executive package. I’ll pick the car up later this week.

Thanks for all the advice. Now as an owner I look forward to becoming a more active forum member.

Welcome! See my signature... I am partial to that car!