Might be wrong but I never heard about chain driven cams at Audi / VW
They're starting to go back to chains now. I believe all the Audi V6 and V8 are now chain and some of the 4 cylinders too e.g. 1.8TFSI and 2.0TFSI IIRC.
FYI, the VR5, VR6, W8, W12 and W16 are all chain driven.
I believe most manufacturers went to belts in order to have quieter engines but obviously they add a big cost to maintenance every few years and are less reliable.