First, these guys do a whole lot more than mufflers. As someone who knows next to nothing about cars, I trusted my father-in-law's recommendation of Mighty Discount Muffler, since he's been a mechanic for forty years. He was right! I've taken my car there three times now, for both minor and major repairs. The mechanics did not take advantage of my ignorance - they sold me only the services I needed, and did a good job on the repairs. Not only that, but when I detected a problem with something they'd fixed, they corrected the problem immediately with no excuses. I will continue to take my car there!
Pros: Good service, good quality repairs