Hog Wash Express is a great car wash place that prides themselves on free use of their vacuums. They have a touch-based car wash that is automated. They accept credit, cash and pre-paid subscriptions - and the staff is usually pretty friendly if you can find them.
Expect to bring a towel to dry your car off. You'll need it because the driers in the wash miss many spots on your car. That's the only reason why they didn't get full five-star rating is because of the need to dry the car off repeatedly with a towel.
Overall, I would rate this as one of the best car washes in the Tempe area ... at least until Cobblestone sets up shop.