Self service car wash in the DC area (Washington: credit card, stations)

[mtb20x]

Does anyone know of a legitimate self service car wash inside the Beltway?

I'm looking for the kind of car wash where you pull into the bay, put quarters in the machine, and use a pressure washer wand to clean off your car. I used them all the time in the Northeast, but they seem to be few and far between down here. I don't have access to a space where I can wash the car myself, so I'm on the hunt for one of these self-wash stations.

Any suggestions would be greatly appreciated! Thanks a lot!

[killabunnies]

I like Billy's in Fort Washington. Otherwise Sam's in Temple Hill is good but there are way more shadier characters out there. Oh and you can use a credit card at Billy's!