"See? You fit fine!" By some definition of fine that doesn't quite qualify, but good enough is good enough.

"The ones in the scrapyard are bigger than these, so I know they probably were better at holding people. Must have gone a lot faster, too!" he says as he carefully presses the gas pedal, then presses a bit harder as it barely budges at first.

Don't mind the nonsense about cars, as he just spouts things stream-of-consciousness. That's totally normal, right?