Moving Ground Vehicles Over Obstacles

I can do some intermediate level scripting, but vehicles are a bit of a mystery to me. I have played with adjusting some vehicle scripts.

One problem I am having is with ground vehicles. I come to a small obstacle on the road or a small hill on the land, and the vehicle is stuck and cannot seem to go over it.

Any suggestions on what to adjust to make a ground vehicle able to go over small obstacles and perhaps even up a moderately pitched set of stairs?

Thanks!

timescale and or linear motor direction might help IIRC... also making sure the front of your vehicle is sloped much like the front of a boat seems to help