Neighbors taking up all the street parking

I live on a small block with 3 houses and space for 6 cars to park on the street (2 spots per house). The houses are all 100+ years old and do not have driveways. I bought the house over a decade ago and have never had any problems with parking since everyone was respectful and generally used only the spots in front of their own house. However, the house next to me got new renters, and they keep getting more and more cars. They now have 6 cars parked on the street and therefore take up the entire block. They only regularly drive two of these cars (there are only 2 adults/drivers in the house), so on a daily basis only 2 parking spots might ever come available. It’s like a war between all the neighbors to get those 2 spots, meanwhile all their cars just sit there in front of everyone’s houses.

All the cars are operational/newer and registered. I’m in California and we do have the 72-hr parking rule, so I have called and an officer comes and chalks the car + puts a warning. But then my neighbor just moves it around the corner for a couple hours, then brings it right back, starting the process over and it will sit until I call again. Do I just keep calling every week?? Or how does the 72-hr rule actually work if people can just move it every time they’re warned?

The kicker is his house is actually one of the only ones on the street with a 2-car garage behind the house! But he doesn’t use it for cars, instead it’s just full of junk. It’s sooo frustrating not to ever be able to park in front of my own house, walking a whole block with groceries and my kids. Once when he was parked in both the spots in front of my house, I tried super nicely asking him if he would mind switching spots with me since I have kids and stuff to carry, and he blew up asking me if I think I own the street and saying I think I’m better than him because he rents. (Which I said nothing even remotely about or implied at all.) So I don’t think talking to him will be helpful.

I’m saving up to add a paved driveway and gate in the alley behind my house for off-street parking, but in the meantime is there anything I can do? Apparently my city does not have a limit on the number of vehicles parked on the street per household. There is a rule about storing vehicles, but if they just move the car every time they’re marked, then it’s not enforceable?

ETA the whole street is resident permit parking only Mon-Sat. I checked their website and it is possible to get a max of 5 permits per house including guest passes, but since they seem to have 6 they must be using one from another address or gotten it somehow.