I just went through a similar thing with the HOA in my neighborhood with my personal vehicles. There is a 17 acre wooded lot across the street, I know the owner and have permission to dump, hunt, park, etc on his property. With the number of vehicles I have and the number of people coming in and out of my house, it's easier just to park across the street alot of the time, never going beyond width of the property of my own house. Some folks from the neighborhood didn't like it...called the cops, got city officials out there, brought it up at the town meeting, etc etc. I was told the HOA didn't have a leg to stand on because a house not being there doesn't mean it can't be parked on (cue future revisions to the HOA policy). However, I was told if anything on the vehicle overlapped the street, I'd be ticketed. I was also told if there were any unlicensed vehicles on the street (ie a buddy parks a trail rig we're wrenching on over there) it would be viewed as an abandoned vehicle and could be towed away. I was also told if an uninsured rig was parked over there it would be ticketed and possibly seized. I also made it very clear to all my neighbors that any time they wanted to have a yard sale, Bible study, party, etc...expect me to make the call to have all those cars ticketed/towed/seized. I also reminded them that having propane tanks visible from the street was a monthly $150 charge, and I volunteered to collect those fees. So from my perspective...if this guy is a neighbor of yours, make sure you don't live in a glass house first.
So to summarize...permission and off the road, ok. On the road...not ok under any circumstances.
