Why not in Norwalk, CT? I can do it there, and everybody knows of my work!
Why don't you move the Boston, open a shop with true %100 handwashing(no pressurized water) somewhere in downtown, with a waiting room with wireless and a capuccino machine, hire college girls to do the washing, and you'll probably make a ton of money from all car freaks....
Most people who live in the city, live in apartments and park in garages where they are not allowed to wash their own cars, or don't have time, or to lazy (me, me, me...)
Also make like a monthly packages, up-to 4 times fixed price with reservation
