No spare tire, Robbie, just a perfectly ordinary Cybertronian butt.

Drift raises a robot not-eyebrow at him. "Hey, I had the name millions of years before I ever went to Japan -- or even heard of Earth, for that matter." He waves his hand in a don't worry about it gesture. "I'd like to think I have a little better fine motor control than that, but then again, humans are usually, er...pretty squishy."