It need to much time to get rpm after start and the bigger problem for me, the caster als abolutely to low. You cant set it from 0 to 7, but to get a plausible feeling for the car, you need 8-15. After i change it to
LeftCasterRange=(-0.0, 0.25, 60) // front-left caster
LeftCasterSetting=50
RightCasterRange=(-0.0, 0.25, 60) // front-right caster
RightCasterSetting=50
it makes a lot of fun.