spinning wheels problem

Hi im a new to this GE. But I have managed to get a really simply moving car. Or actually i dont have a car only wheels =D. But my problem is that my wheels front wheels arent spinning when I am turning =S I have tried many things but nothing work. Any help?
I will but a link to my blender file:

http://www.4shared.com/file/34060906/42c8ca9f/tire_simulaatio.html

And a another question, if I may ask? How can i get my car accelerate?

Deleted!!!

Deleted!!!

Okay i got it now thanks for your help.