Why are there suddenly so many car washes?

I really hate sounding like a broken record but this is just another instance of how low property taxes and the absence of land value taxes massively benefits low-value businesses.

The real business of car washes is real estate, it's profitable enough to get 3-4x leverage with a low interest loan.

TBH I think real estate used to have high information asymmetry between local residents and large investors; low property taxes and generous loan terms under this primarily benefited small businesses, individuals, etc. I think the internet and increased observability into far away projects erased this (a ring camera costs a billion dollar PE firm and Single home owner the same); now the same policies we have had are allowing easy arbitrage between low cost fed/PE cash and predictable "dumb" business categories; car wash, self storage, etc.

I take pride in the fact I haven't been to a car wash in probably 3 years and have likely gone myself less than 10 times total. Rain and the occasional wet rag is good enough for a depreciating asset.

Yes but they still degrade relatively quickly when managed correctly so a burst of pollutants whenever it rains is better than a constant low level exposure from people washing their cars all the time.

Regions where it rains frequently like the PNW have rain gardens, vegetated swales, catch basins/filters, and other mitigation strategies all over the place whereas e.g. California might just have them throughout the drainage system like at the end of the LA river.

This existed in CA too, haven't seen $30 prices - oil+wash+hand dry... but those prices ended around 2005ish.

The ones that don't get torn down and replaced with something else. no big deal so long as you allow people to try things and fail.

The irrational market isn't a problem for politicians it is for investors: people with money, let them learn their lesson. As for the jobs lost, at least the rich investors paid them while the wash was running, they will move on. The jobs are not high skill so no real loss when they are gone.

In my specific region of the US, you're more likely to see something between a small 'automated' facility where your car is pulled along a sort of 'assembly line'[0][1] or a somewhat larger 'DIY' car wash where you might have to do your own start stopping or are practically given a squeegee cleaner, some colo(u)red water that may or may not have cleaner, a mounted pedistal shop vac of some sort, and a race against the clock based on how many quarters you put in.

Or, sometimes a combination of the two.

The setups for the DIY shops are usually fairly cheap IMO (Just looking at what's going on at them and the BOM) and the main thing outside of market saturation is having a good ingress/egress setup (If one sucks to get in and out of, folks won't come back.)

That's not to say that there aren't hand car washes as well, however I only tend to see those where I grew up (not too far from here, mind you,) or when it is some sort of school/church/etc fundraiser.

The weird thing you can run into in some cases, even at the automated shops though, is either weird 'implied consent' about extras by folks on one end or another of the line, or in the case of any of them, 'memberships' that are priced to where you'd really be following that 'one wash a week' rule to get your money's worth.

[0] - Often with a warning that they are not responsible for damage to vehicles older than X years and/or with more than Y miles

[1] - These can be surprisingly small, to the point some gas stations have one on the side and a purchase gives a 5/10c discount per gallon. Which, to the general point of 'pennies on the dollar' they made money on long term.