Doing stupid stuff to stupid people and documenting it (IE calling the HOA, if they even care) usually results in having to look over your shoulder for a while. If your story is true and they're actively uncooperative, then drop the issue for a while.
1. Check to see if the local PD has jurisdiction over the HOA/city parking laws. We had local Barneys in one HOA sub we lived in that loved the revenue from enforcing the parking "laws". Nothing gets dumb @sses to move their cars like a stack of parking tickets.
2. If that doesn't work and you know there's no cameras around, it's a shame when vehicles randomly have issues like not starting or tires that are almost flat.....
(True story, had a guy that would hunt (poach) the woods behind our houses and park in our subdivision. After a run in with both me and our neighbor and neither the fish cops nor the real cops taking any action, he pulled in for an afternoon hunt and came out in the dark to 4 missing valve stems. This was basically the only "private" place to park and access these woods, and I've never seen his truck parked at any of the other areas in subsequent seasons, so I think it worked.)
