The anonymous nit who reported the four cars also violated a code - not government, but neighborhood civility. He/she should have made an introduction at an opportune time, inquired about the four cars, and upon learning that it was due to a temporary visit, inform the neighbor of the code and politely requested that they likewise try to limit any minor violations of that in the future.
That approach would get my effective compliance along with communication if I was expecting any infrequent future visits resulting in temporary short-term violations. The approach the cowardly nit took would result in something like that “toilet bowl planter”.
What next? County permits for the exact number of persons occupying the home? Uncle Henry & Aunt Harriet is going to be spending the weekend someone better go by the Zoning Office. Some may say it's not the same thing oh yes indeed it is.
Corruption and abuses of power usually get their foothold by precedents being set at lower government levels as well most tyrants get their start as corrupt local officials and work up the political ladder into state and federal offices and positions bringing their ideals and abuses of powers with them. It's A Parking Tax. Permit my eye.
This is why I don’t live in a neighborhood. I live on a farm in the County. I have to use binoculars to even see my closest neighbor. I wouldn’t have it any other way.