A muffler, usually bought on Ebay, is welded to a stock exhuast system. It is usually bought and installed on Civics, Cavaliers, Neons and others that do not have heavy aftermarket supports. Because it is installed on a stock exhaust system, it usually sounds like shit. Kids who live with their moms that work at McDonalds purchase these coffee cans.
Yuki: Hey that kid has a nice car but why does it sound like shit?
Ray: Cuz that guy's gotta coffee can off Ebay.