My suburban neighborhood is also not a homeowner's association, but all of Sacramento County has codes that apply everywhere. One is not allowed to do "major repairs", even behind closed doors in their own garage. I bet the auto repair shops got that one passed. Of course it comes down to whether snoopy neighbors complain. One co-worker is regularly informed on by his retired neighbors, but he always manages to get the engine back in before the inspectors knock. I'll bet the ones calling also rant about individual rights and less government, though they love their welfare programs.