I saw this earlier on-line.

they were great!

My guess... it's against the local zoning ordinances.  There are communities that don't allow a motor
home or camper parked overnight in their neighborhood.  
There is zoning that says any vehicle on YOUR OWN PROPERTY has to be registered and insured to
state codes.  No unlicensed vehicles.  

The cop did his job, and seemed to do his best to keep from giving these guys a ticket.  

Clean-water laws and "storm water management" practices which are all local laws brought about by the leftist crazies who pushed Agenda 21.

evrything is becoming a felony

Perhaps it was staged.

Some communities ban things like car-washing for snobbery type reasons. A lot do ban it for environmental reasons, but I'm going with the snob factor in this instance, as my guess. They probably ban tree forts and clotheslines also.
I didn't catch where this is, but some affluent communities do have older homes. Perhaps this area was hit by the mortgage bomb, now there is a house in a neighborhood of single-family, owner occupied homes, now it is being rented out to someone who doesn't fit the neighborhood, so the neighbors aren't wanting them there and are using every method at their disposal to try to push them out.
The guy is young, and unaware of the rules, so my guess is he isn't the homeowner.

From what I can surmise viewing the video, the guy may be running a used car shop from his home.
The cop asks who painted the car, and the cop said that there was a different car there previously
with mismatched plates (not legal for that car).
Again, zoning in some places prohibits any vehicle not registered.  
Without more details who knows what the actual situation is.