If your car is dirty, you can take it to Wash and Roll, an automated drive-through car wash. You may not remember the experience, however.
Marvel Comics continuity
Devised as part of a nefarious scheme by Ratbat, Wash and Roll car wash franchises were sold prefabricated and set up at a number of locations -- including Witwicky Auto Repairs -- as a front for a gas-siphoning operation. The car wash's flashing lights and blaring music made it an entrancing experience for customers, drawing in huge amounts of business. But humans who drove their cars through the Wash and Roll were literally hypnotized by flashing lights of the car wash's stroboscopic opticon. The hypnotized humans were compelled to drive to a Blackrock Industries facility at night and drain their vehicle's gasoline into the Decepticons' storage tanks.
An initial trial proved only partially successful; the humans were hypnotized, but the effect wore off after only one fill-up and siphoning. Ratbat promised that the improved Wash and Roll II would keep the humans under his control forever!!
The scheme was undone when Buster Witwicky made it through a Wash and Roll un-hypnotized because he had been distracted and didn't see the flashing lights. Smashing the car wash's huge electric sign produced a flash which likewise de-hypnotized the other hypnotized humans; they then drove off Ratbat and Laserbeak, who had been overseeing the operation. G.B. Blackrock himself had also been hypnotized into collaborating with the Decepticons in this scheme, but once freed promised to used the stolen gasoline profits to aid the poor of the Pacific Northwest.
Transformers film continuity
After arriving on Earth and adopting his disguise, Signal Flare secretly acquired an unspecified position at the Wash & Roll. It is unknown what role a MASER tank might fulfill at a car wash without raising suspicion. He may be completely in hiding, even from the Wash & Roll staff. Regardless, his fellow Autobots are aware of his location, and come to him when they need repairs or refills.
There may be only one Wash & Roll in this continuity, but it is stated to be near the Witwicky home, much like its Generation One counterpart.