Robyn supplied this description:
Covered in bumps, larger than a refrigerator, makes a metallic clanking noise, the envy of all that gaze upon it.
This was actually my second idea. I should have done my first. Oh well. And no, I can't draw a motorcycle any better than I can draw a car.
and Debra supplied this one:
Heavy, dark, glowingly enthusiastic, and about as subtle as a box of rocks.
I like this one.
It may just be me, but in just three attempts at this the descriptions seem to have shifted from the obvious to the totally obscure. Still, keep them coming. I'm enjoying it. Comment here with new descriptions.