How to use collision between meshes?

Hi,
I am trying to creat a mesh which acts as a street and then another mesh, a car, can travel on it.
Now if my road is on an incline or decline, my car still remians on the same place, so going under or over the street.
I am trying to use to make sure it slides over the street but it doesn't seem to work.
Any ideas? Thanks in advance.

maybe something for the tokamak physics engine?

Study the collision info.
Give the car an id number and the road an id number.
Then check for collision between them.

The way I read it , you want your car to align to the surface of the road when the road is going up/down hill.

I believe there are examples of how to do this in the code archives.