I'm a bit of a self-serve car wash connoisseur and use them all the time. Keep in mind that I'm a guy who knows how to detail and has a regular hose and bucket home facility as well as hot and cold power washers, etc.
So it's not like I have no choice but to use them, I just like them that much. I washed my DD at one yesterday after back-to-back storms in L.A. left my car pretty filthy. They are just so convenient if they are good facilities and you know how to use them properly.
98% of people don't know how to use a SSCW properly and that is where the hatred and the profit comes in. People take WAAAY too long to wash their cars and/or run out of time on the coin box w soap still on the car, etc... There is an art to it.
Secondly, the reason that many people don't use them or hate them is because in much of the country, the SSCW business is seriously ghetto. Nasty facilities w/o up-to-date technology or payment systems, etc. I've used them everywhere while driving cross-country and they generally suck in the heartland. In Los Angeles, while there are some out of date, crappy ones, most are state-of-the-art and do extremely well. The ones w no capital investment showing are generally empty and probably don't make much. Strangely enough, I've never seen any evidence of vandalism or tagging at the ones I use, even though they are definitely in the congested, urban locations.
As far as the "cash business" aspect being discussed, if you mean unreported income, I cannot imagine how that would work. Could you simply trade the quarters in for paper $$ at a bank every day and stash the cash? Or are people thinking of spending thousands of dollars in quarters on purchases in the future?
The major breakthrough in the industry from my perspective is cc readers. I never use quarters anymore, just pull into a facility and use my debit card. The quarters were such a PIA. I spend more, (as does everyone else), and who gives a schit? What is $6 or $7 on my VISA to wash my car w that convenience? It's fast and I get it really clean.
The card readers have been a game-changer for the owners, the places are almost always busy and I know that the $$ per visit is WAY up. I've talked to owners in the midwest who don't have the modern card readers and they have dumb excuses of why they don't install them, too expensive, etc... They just don't get it.
Here is one from my most commonly used SSCW, on Santa Monica Blvd. and Cahuenga in Hollywood:
