First impressions

[thelusiv]

I say get the speed from somewhere upstream from the wheels. The best place is probably the transmission output. That will still give you the same reading as the wheels, the speed will still spike if you burn out, etc. If you want the reading to be wrong when wrong-size tires/wheels are used, then we'll need something in the car definition file like "stock-wheel-radius" that can be used to calculate speed no matter what changes are made to the actual wheel values.

edit: about tires, heat, smoke, etc....at some point it'd be nice to make the tires "wear" and have this be dependent on how much abuse you give them. I don't think it should necessarily be a perfect physical model of tire wear, I'm sure there's some way to approximate what percentage of tread is used in certain time quantums and under certain conditions somehow...