You can indeed get the normal of a surface from the cross product of the tri's verts, but that only tells you the direction which the Y axis of your object should point when on the surface.
The big problem here is this isn't how you're supposed to simulate vehicles on surfaces. :-) It's all much simpler if you simply pull each wheel downward and stop when it hits something, and then calculate the angle of the car from that each frame. But to so that I'd use align to vector, which he doesn't have. :-)
The big problem here is this isn't how you're supposed to simulate vehicles on surfaces. :-) It's all much simpler if you simply pull each wheel downward and stop when it hits something, and then calculate the angle of the car from that each frame. But to so that I'd use align to vector, which he doesn't have. :-)