Imo cars in gt5 generally do not pitch and roll anywhere near enough. Brake hard and the pitch forwards is too gentle, softly sprung powerful cars don't squat down off the line enough, and normal road cars from the 90s have far too much body control in aggressive direction changes. Plus cars never lift an inside wheel whilst cornering.
There are a few exceptions. The premium S2000 is much better than most, and the e-type actually looks like an old car, unlike most of the others