Those nasty high pressure hoses can also reveal hidden rust. My last car came out looking older than it did when I drove in. I guess the paint was holding the wheel well and rear window moldings on. I don't go to those anymore.

Have you seen the newer automatic ones where the assembly moves and rotates around the car while you sit in place? I wonder how much pressure they use relative to the DIY places.

I see them just about every other tank of gas in the winter. The drive-thrus at the gas stations aren't extremely high pressured. If your weatherstripping is old it might leak, tho

But.... don't open your window in the drier part. That'* some high pressure air. Just a little advice from your Uncle MOS....

lol just leave it to mos, latley ive been using the autowashes too
A good can of Gunk engine foamer will do great, use on a cold engine however. You may wanna cover your coil packs, infact, i would.