Maybe a splash shield rubbing?

They are pretty close to the rotors.

 

Interested too. My 2012 R8 GT does EXACTLY the same thing and just last week I narrowed down when it does it including it doing it more when the wheel is turned one direction vs the other including stopping it by a greater turn to the right. I know mine isn't the brakes either and its metal on metal so will have dealer check the splash shields with the suggestion above the next time I drop off the car.

 

Interesting, I am wondering if there is a way I can check this?

But, with that said, why would this get worse over time and worse with heat?

 

I guess it depends on how comfortable you are working on a car. If you have done brake work before, it's super easy to take the splash shields off (you'll have to pull the rotors to get to the screws holding them on), then put it back together and see if it goes away.

That's what I'd do.

Simple test and it would solve your problem.

The issue is, if the noise is gone when the splash shields are off, you might have poor initial braking performance while driving in heavy rain.

This can absolutely get worse with heat as things expand and contract with temp changes.

You've done everything else it sounds like, this would be my next step. I'm certain the dealer will argue with you about trying this so you might need to do it yourself if you're comfortable of find an independent.

 

Or something is lodged between the rotor and the heat/splash shield. When it gets hot it squeals louder.

 

Not the splash guards, dealer has no idea. Back to square 1...

 

So you don't think its a brake issue but have you replaced the brake rotors?

I had very much the same problem and it only went away when the rotors and new pads were installed.

My noise got progressively worse as time went on prior to the change.

It only happened at low speed after about 10 mins when things got warmed up.

Does the noise somewhat disappear when you feather touch the brake pedal after you first hear the squeal on normal braking?

There was definitely no wrapped discs on mine as they tested true straight on the machine when they took them off.

 

Okay, here it is. Finally fixed.

After replacing the rear parking brake pads on both sides, both rear rotors and pads, and doing about everything else in the book, the verdict is in...

The rear parking brake caliper was the problem. Apparently it wasn't holding its position and was causing it rub against the rotor and that was causing the squeak. After 5 weeks in the shop and lots of new parts, its fixed. Yikes what a nightmare.

 

Hi, I have the same problem on the rear right rotational squeaky sound too. I have replaced new rotor on both rear, and also both brake pads but big rear brake pads have not changed yet. The sound got louder after 10mins driving, and turn into left will worsen the noise.

How did you fix it? You mentioned was brake caliper's fault? How was it fixed? Please assist. Thank you.

Audi 2007/08 Black R8 V8

 

Thanks for reporting back in. Some people just disappear after they get their issue resolved, leaving a dead-end thread for the next guy to have the same problem.

 

I had a very similar problem with the front left. Only seemed to make the noise when warm. Over a few weeks it got progressively worse. It turned out to be the CV joint. Apparently Audi have come out with a new type of grease and the dealer repacked it and it was fine after that.

Might not be your problem, but worth checking so that you can discount it.

 

You need to REPLACE the rear parking break caliper.