The rule I try to follow is to dress 1 step above what you wear to work in. So if they wear jeans and a t-shirt I'd wear casual slacks and a polo or collared shirt. Be well groomed (shower, shave, recent haircut) and make sure the clothes fit well. Showing up in a power suit for a job like that may actually work against you. You don't want to give the impression you can't get your hands dirty..***:D
I'm interviewing at a small (10-20 total people) automotive business. They make street racing aftermarket add-ons and want people who "fit" their type. It's one of