There are certain types of sports cars and other vehicles where you feel like you are going dangerously fast, where if you were going the same speed in a normal car, it wouldn't feel fast at all.
There is a concept with a name that I'm too lazy to look up, where if you make a car safer, people subconsciously drive more reckless because they think they can get away with it. Because of this concept, a lot of safety features such as air bags seem to cause almost no reduction in traffic deaths, or a much lower reduction in traffic deaths than was predicted.
Anyway, if your car detected dangerous driving conditions, and very subtly adjusted itself to make you feel like you were driving faster than you actually were (by making the wind sound louder or adjusting the shocks or something), it could make people drive safer without even knowing it. But if it wasn't subtle enough and people realized when the car was doing it, it would ruin it due to the concept mentioned in the previous paragraph