I'll throw in my 2 cents... Half price today... Not a big fan of the cars. We call on banks on schedule and may have 10 cars. We do detailing so sometimes it can be worth it if we have several details. But we also have extractors, waxes, buffers, compounds... Basically lots of useless inventory. Since that is how we began, it is easier for us to keep on doing them. But would I market to them - no. I think Scott Stone started in a similar fashion and redirected his efforts to high volume, pressure washer oriented accounts vs. a car wash orientation. I am just assuming and don't want to speak for him. I think your marketing and advertising efforts would pay off more elsewhere. Lots are cheap. They want $75 for what we EASILY get $250 for.
One exception though. You are in Florida. Much better market for car washing. Guys in Destin bring it in - but it is a detail focus.