i can outrun cars now. this should not be the case.

i must be having a conflict because it's not working for me at all. i'll have to try it on a different save file or a new file

In 1.0.5 I've been able to drastically increase the car (only the car) speed to 75 km/h.

There is a trade-off, which is that as these DMV vehicles get faster, they are capable of jumping obstacles like cliffs, rocks, individual trees. In some ways I like this a lot because when you're really zoomed out you don't even notice those small objects the vanilla car runs into.