Muffler's hair a sign to replace it

Dear Tom and Ray:

Recently while looking in my tailpipe, I noticed a small amount of what appeared to be human hair sticking out. I began to pull on it, and at least 10 feet of strung-out human hair came out! How, where and why did it get in there? It's a 1996 Saab.— Harris

Tom: Well, Harris, you've discovered where the Hair Club for Men gets its replacement locks. When they put you on the list, and say they're waiting for a donor, they're out snooping around supermarket parking lots.

Ray: It does look like human hair, Harris, but it's really just plastic. It's sound-deadening material that's used inside certain mufflers to slow down the exhaust and muffle the engine noise.

Tom: And when a muffler gets worn out, the insulation can start to escape and work its way down the exhaust pipe, until it looks like you've run over ZZ Top and are dragging them down the street under your car.

Ray: So you need to replace your muffler, Harris. It's not urgent, but you want to do it before it gives up all of its hair — and looks like me!