Car-wash companies are increasingly trying to ramp up profits by adding self-serve pet-wash stations. PD McLaren Ltd., which manufactures the washes, reports that sales have significantly increased this year. It sold just 40 units between 2000 and 2002, but has already sold 80 in the first six months of this year. “Three years ago people laughed and said, ‘How stupid is this?’ " says Pete Weiblen, marketing manager for GinSan, another company that makes pet washes. “Now, all of a sudden, they’re all over the place.” Experts estimate that there are more than 700 combo car-wash/pet-wash companies nationwide; the self-serve washes are also popping up at condo complexes and as stand-alone businesses with cutesy names like Shampoodle and Dog Gone Clean.