At Bud and Ben Muffler and Front End Service, the signs and statue are very clear. It's a muffler shop, and there's a sharply painted fiberglass muffler man, some 20 feet tall, holding a large auto muffler. Labeled "MUFFLER."
Elsewhere in Dallas three more Muffler Men -- Happy Half Wits -- promote variations of the same services, for Ken's Muffler and Brakes. You can visit all the four statues, if traffic cooperates, in about an hour.