A prototype of what? A rubber duck? Probably a piece of plastic filled with air, so you can find out whether it will float. No seriously, give some more information what you are even asking about please, or people cant help you.
Sorry. Lost my train of thought, and then blindly hit the submit button. Anyway I was wondering what would be the quickest way to get my prototype vehicle moving. Like what is the most basic way to set up a drivetrain, frame, and suspension system.
I would suggest you start by making some basic jbeam structures, a box is the easiest at first, then move onto more complex things. When you think you are ready to tackle a car, have a look at how the default vehicles are made (e.g suspension, structure ect..) and try to make something similar.