I find that players can survive crashing their vehicle going over 100 km/h. In my opinion, this is very unealistic as by looking at the vehicle model while sitting inside a car, the seatbelt is not on the player. In real life, if someone crashes their car at a higher speed than 70 km/h even with their seatbelt on there's little chance for survival

As such, I believe the chance of death should be higher when driving faster than 60 km/h, and I also suggest you add a "seatbelt on/seatbelt off option which will make the seatbelt put itself on the player and increase the chance of survival.