Haha! It's like there isn't any suspension. Like the vehicle skips up without the suspension taking the impact then pushing the car up after you're on the curb... Hard to explain....
The worst case is the Faction without Benny's upgrades. I contacted R* and even sended them a video. They answerd me they are gonna look into it but nothing changed so far. The car react like a brick when hitting the curve and can sometimes even launch into the air. That's the reason why i don't drive it mutch.