I have a few month old Q5 that from time to time there is a very loud bang inside the car almost as if something hit the car... I can't seem to duplicate the problem as it happened only 4 times so far... It is so loud that you would suspect that a tree fell on the car... I think there may be some radio malfunction however it has done this with the radio on or off. Anyone else experience this issue?

 

16 costly car noises

 

I know this is an older thread but there are several threads for newer Audi models with the same problem.
Check out this one for example over at the A6 section: Loud crashing sound in a new A6

Check with your dealership and advise them about this Stereo problem - maybe they have a fix by now - and maybe it is something entirely different but at least you are not alone with this issue.

 

We had the same problem with our new 2012 Q5 - A loud bang as if a cement block fell on the sun roof. Scared the heck out of my wife and me. Happened a few times when the car was new. Nothing to do with radio. We had this checked out with the dealer. They could find nothing. Now 2 years later it happened again. That's why I Googled the problem. email me if you want to join in the pursuit. I am a lawyer looking for people who have this problem to get Audi to recognize it

 

If you have a loud boom problem on a Audi q-5 my Email address: shdeutsch@gmail.com. I hope this does not violate forum rules.

 

Have the same problem, i thought something was dropping onto the sunroof or it was popping.

I found the issue, look at the hinges on your rear deck that moves when the rear door is opened. There are three, on mine one is broken and since it is spring loaded, when it is open and shut the pivot piece is binding and then snaps loose causing the noise.

Hope that helps