Rusty Muffler Edit Meaning

1.

Feces left around the anus. The situation one finds oneself in when, having defecated, one finds that there is no toilet paper available.

I had a crap this morning, but there wasn't any bumwad, so I had to go all day with a rusty muffler.

2.

what my dad says after fucking my mom in the ass

damn kid, your mom sure does have a rusty muffler

See Matt

3.

Used as a code word over the phone when talking about marijuana cigarettes, joints, reefers, doobies, chongers, etc., etc....

Hey man do you got any rusty mufflers?

See stoner