I ordered the B&O on both my A4 and R8 and it is a lot cheaper on the A4. The system in the A4 actually has more speakers and has slightly more power so the only explanation is that Audi thinks that they can charge more for the R8 and get away with it (which they do sadly).

So far the B&O is completely wasted in the R8. When I do listen to it instead of the engine note I found the system gives excellent frequency separation but a bit artificial for my liking. I am going to pick up my A4 tomorrow . Let's hope that it will be better in the A4 with a much quieter environment.