...The interior sounds are not bad at all, but when in the "replay" camera mode, GT:S sounds, hmm, more brrrrr while in AS it's bzzzzz. Okay, so that's not a good way to describe the nature of the sound, but AS's sounds more realistic/closer to what I've heard from the car itself. GT:S's, on the other hand, except the interior, sounds almost like it's a sample from GT6. Having seen all the improvements PDI made regarding "engine noises" in all 'em beta videos, it's a bit disappointing, really.
As I said before, hopefully they are working on improving it.