Our local coin op car wash seriously frowns on open hoods in the wash bays, and backs it up with the threat of $250 fines. They say the water is recycled, and given the storm drains go straight into to river or sound, I don't doubt it.
Of course, there are a few unnamed spots that will let you use the spray gun if you tip the operator and send him across the street for coffee..
.

__________________
95 E300D working out the kinks
77 300D, 227k, station car
83 300CD 370k, gone away
89 190E 2.6- 335k, no more
79 VW FI Bus- 145k miles, summer driver
59 VW Beetle ragtop- 175k miles
12 VW Jetta- 160k miles