Building a car or motorcycle?

[gamedevbynight]

I have my problems to build something like a car or motorcycle with contraints. Is there an example anywhere?

I want to have 2 circles as wheels and a rectangle as body. I want to accelerate using angular velocity on the front wheel.
It runs if I only use 2 wheels. When i add the body it's acting strange. I don't know which contraints are the right ones...

I want to build something like in http://www.tg-motocross.com/ .

Thanks for your help.

[T1m_]

I sure there was information about it in this forum. Try to use search.

I can say from my experience there is some difficulties to find good values like mass, friction etc.