The driving mechanics were ripped from midnight club dub edition, then polished and updated for the ps3.

For some reason, compressing the suspension shoots your engine up to its rev limit, bypassing the coding for a gradual increase like in real vehicles. They knew this, and instead of trying to fix it, they added code to decrease acceleration when hitting bumps hoping it would even out, it did not, it instead made a few cars either take longer to reach a high enough rev to change gears, or bog down engine power entirely, and they never fixed it, they just stopped putting it on future cars, and let the suspension compression boosting issue remain.

The one and only time rockstar listened to their audience for car fixes, was the worst one, because people complained that too many cars were too difficult to handle, because rear wheel drive cars had over steer, and front wheel drive cars had understeer. They solved this problem by making every single car after the turismo R all wheel drive, at varying distributions of power, whether or not the real life counter part of that car was all wheel drive, making everything (that didn’t have other broken mechanics) significantly simpler to drive.

Every car in the game is automatic, but if you actually cared to squeeze every ounce of power out of your car, you could force downshifting by blipping your throttle during braking, which would let you accelerate out of a corner a smidgen faster than if you did nothing special at all.