look up any word, like sweetest day:
Verb; The act of ramming your vehicle into the rear end of another vehicle at a considerable speed.
-"Damn, that guy was going pretty fast when he hit you"

-"Yeah, he muffler fucked me pretty bad"
by Whiskie December 01, 2009
A fag who fucks mufflers, usually named jimmy
look at jimmy...that muffler fuck!
by Titts December 04, 2007