Look up any state requirements for signage. If you can find a sign on your block that's obscured for any reason and get a picture, you can use that in court. Even if a few signs that weren't in the thieving PoS's pictures happen to disappear ... wink-wink.

Also, do you have commercial plates on your truck? Are there any exemptions for commercial vehicles of tradesmen -- I'd find it hard to believe that plumbers or electricians have to move 100 ft every 2 hr.