Stick the powerfull 900cc bike engine in a mid sized hatchback and see what happens , you'll then understand why a bike engine can be 900cc and have lots of horsepower, and an engine that has to push a heck of a lot more weight can't.
Every unaccompanied test drive i've done, i've just been given a "trade plate" to stick on the dashboard, this means you are covered under the traders policy.
Good one matey!!!!, I am on the second "level" now (1-2) and I am taking it SSSLLLOOOWWW because now, if I die, the enemies get tougher, and I don't really want that!!!!