I totally agree with xSNAKEx, the tyre sounds are IMO, the best sounds in the game (and are rather good even relative to other games). You get this lovely, rough, "scrubbing" noise during understeer which I think sounds very accurate.
This, really, is symptomatic of something inherent in GT - inconsistency. The stuff they get right is uncanny in its accuracy, and the half-baked stuff seems really, truly awful. Compare Premiums and Standards, tracks such as the Nurburgring, Silverstone and Willow Springs to Trial Mountain and Grand Valley, the accuracy of the lighting/weather system to the sounds. When they get it right, it's brilliant, which I suppose makes the lazy stuff even worse in comparison.