I have 2008 v6 cayenne
I have this problem since I bought this car about 2months ago.
Whenever I brake while reversing, I can here a loud clunk. Then, the clunk appears 4,5 times more with each braking and stops.
Somehow I figured out that I have to drive for a while to hear the noise.
I have been to dealer a couple of times and was told that this is normal because 7 out of 10 gen2 cayenne have the same problem.
They first said it is probably because of wet weather making the brakes to slip, but then they said the sound is comming from the drivetrain. The sturucture of differential gears, drive shaft and etc are the cause of noise. They said its safe and there is nothing to do about it.
However, I think the clunk is pretty serious because it's very loud! Anybody has solution?