Break pads, how long do they last?
 

I know it depends on how you use the car but just to get some sort of indication, how many miles before your first change?

My S8 is still new and with its original brake pads, if my old Q7 could serve as an indication, I changed my first front brake pads on 42k kilometers, so about 26-27k miles.
For A8, considering its lower weight, I think at least 35k miles would be a safe bet.

I am at 39k km on my original pads and the front ones looks to have a lot of mileage left but the rear ones look to be ready for a change.
On my old D2 there was no warning on the rear pads so had to check them manually, anyone know if there is a rear wear sensor on the D4?

There is a rear wear sensor. My fronts were done at 40k miles and the rears at 58k.

was that original on the rears?

the D3 would eat the rears a bit quicker than the fronts. just as a comparison point....

I can't be sure, I'm the second owner. I do know that I won't be taking it to the dealer for that service again, $1200 to swap out the rear pads and rotors is simply staggering, even considering the car. I'll do it myself in the future and keep the change.

you might get the dealer that you gave that $1200 to print the service records for you. they should be able to pull them up.

i got a quote for the rear pads/rotors on my S8, and was pretty much same as you. $300 for OEM parts and 1 hour of my time was what it cost me in the end.

one thing i really like on my D4 is the rims that come with the sport diff make for very easy inspection of the pads/rotor with out having to pull the wheel.

For a little more hands on info here...
 

What you should find more specifically on a D4 is pretty the same as either my 2013 Q5 or my 2006 D3 A8. That is, the front pads have a built in sensor set up, while the rears work off the parking brake motor and auto adjust. It does mean a light will come on when the pads wear low.

$1200 for rear brakes is way too high as noted, and you can buy dealer rotors and pads on line (if you want OE) for way, way less. As in, the labor doesn't really add up here. The hardest part of the rear job is actually that you need to open and close the rear brake calipers electrically to do the pads. In the front you do it the conventional way with a squeeze tool or clamp. That means effectively in the rear you need to own a VCDS/VAG COM cable. You can't do it just by winding them in, squeezing them with a clamp, taking off the parking brake motor, etc., and if someone does it that way invariably it screws things up in the rear caliper and/or parking brake motor.

Net, for DIY on rears you (or an indy shop) needs a set up like VCDS and not just the parts and basic brake job knowledge. It actually takes as much or more time for the computer side as the mechanical work takes if you don't have the regular experience doing the VCDS routine. And yes, the mechanical side is relatively easy, compared to most Audi mechanical work and brake work generally.

Hands on..there are quite a few vids on youtube that describes changing the rear pads on the D3's. The brakes looks very similar to the rear brakes on the D4, anyone know if they are the same?

If the D4 is like my A6, you can do the rear brakes easy without a VAG COM. Just remove the two screws on the motor and back them off with a torx bit, re-install the motor. Nothing too it!