Don't call it a parking ticket when you claim it, call it a $15 parking fee. After all, there's no reciepts for those spots where you just stuff bills through the little slots so they can't require you to have reciepts for every time you parked your truck. Besides, the best spots are expensive, everyone knows that! If they only get ya 2 days a week, that's just $5 or so/day.
Or if you don't claim it as a business expense, claim it as a local parking tax. After all, everything paid to your local government is a tax, right?
(FYI, I'm not a tax lawyer.)