Giving car wheels grip?

[Swindel]

Hey,
I finally made a steerable car, but it drifts like mad, which can be fun, but also annoying. Is there a way i can like turn off the drifting? Like, give the wheels more grip? I tried playing around with the magnet properties but that didnt change anything.

Also now that I am already asking a question about cars i migth aswell ask another one;
I have 4 motor joints, all called "Go! 4WD" So I get 1 slider, so far so good, but how can i assign joints to a key on the keyboard? Is it the same for all 4 joints? Then the same with 2 servos for steering?

Thanks,

here is the link to my drifting car.

http://sketchup.google.com/3dwarehouse/details?mid=cdc9b8a73b8a81f91a40465e69e8afdd

edit: I have windows vista, sketchup 7 (Free), SketchyPhysics 3 beta (or something like that )

[Davidfi1]

Is it OK to upload RC1 modules to 3dwarehouse ?

You could look for car modules uploaded to this forum and see how it was done before.