There are many examples in the forums about slope angles and the platform behavior. You should do a thorough search, I am sure that you'll learn a lot of things from those examples.
Here is a rapid prototype of a vehicle that behaves somewhat the way Blaster Master: Overdrive does (or at least like a video I saw on Youtube).
html example: http://www.eli0s.com/Tests/VehicleSuspension/
Use Arrow keys to move and Spacebar to fire.
I put it down in a very sloppy way, I didn't even bothered with mirroring the player sprite when changing direction. It does the job however, at least in my opinion. Please note that I strongly recommend using different sprite objects for collision detection on the ground, not the actual graphics.
Here is the capx. In order to work you will need the neat Light behavior made by rexrainbow https://dl.dropboxusercontent.com/u/577 ... light.html
[attachment=0:17g9hl5d]VehicleSuspension.capx[/attachment:17g9hl5d]
Finally, Firefox gives terrible results, at least in my system. I don't know if this is related to the Light behavior, the particles or something else. In Chrome it plays just fine.