My father-in-law pulled a coleman electric washer out of his neighbors garbage in 2005 and gave it to me, said it did not turn on. I replaced a wire and repaired a simple on/off switch.
It's hanging in my garage on the wall and I have washed the fawk out my Jeep so many times I can't tell ya.
It's just enough pressure to get all but the large clay/mud clumps packed into deep pockets...but not so much that I'm penetrating rubber seals on electrical plugs in the engine compartment. A 10 year old kid can wash your RZR from set-up to finish and not harm a damn thing.
gas powered is what I use to clean my brick house, and I borrow one.
Check out flea markets,garage sales whatever and chances are you can find a used electric REAL cheap that will last quite a while and not take up much space and zero gasoline.