If it's a persistent problem, and a tow truck isn't an option...
Get a set of cheap car dollies, then you can move it out of the way. THEN you can place it perpendicular to the parking spots with the bumper at that support beam and he'll be stuck until the blue car leaves.
I think the better option is to start by moving it to the correct spot twice then the third time pull the evil. They're truly asking for it if they don't stop after the first or second time their truck isn't where they parked it