Back in the 1960s it wasn’t uncommon to see scores of muscle cars like Mustangs, Camaros, and the like lined up at the local exhaust shop to have a set of Thrush’s red Glasspack mufflers installed.

It remains a fact of life that many performance enthusiasts don't realize what loud exhaust systems do to the nonenthusiast. Consequently, those who react negatively to noisy rods, vans or bold street ...