I didn't know there were any car washes not using filtered water left in Phoenix, but apparently Full Circle's one of them. While even coin-op washes boast "spot-free filtered water!", I had to break out the quick detailer spray and a microfiber as soon as I got home from Full Circle--water spots galore!
This was after the attendant had done my towel dry, mind you, and wiped down most of the water but left my mirrors soapy. And picked the remnants of the receipt out of my windshield cowl, because the other attendant helpfully left it tucked under the wiper blade when he sent me through.
Sure, for 4 bucks I didn't have to get sweaty in the humid summer air (well, at least not until I came home and had to clean up their mess)... but I don't think it's unreasonable to think "Exterior Wash" shouldn't be synonymous with "Careless Wash."