A place I can trust not to horribly scrape my car and to (mostly) get out those hard water stains from sprinklers is this Terrible's. The $6 wash is enough for most cars; at $10 you get a paper towel and an air freshener, and Rain-X, which is about as useful as leprechaun insurance most of the year.
But they do scrub your car down and have free vacuum stations for you to use afterwards! It's a 3.5 star affair.