If you have time on your hands and are bored. You can strategically park it outside or near their dealership and anyone that asks you just tell them.
I have seen photos of Ford Falcons being parked outside a Ford dealership with lists of issues that the dealer won't honour within the warranty period.
Though you may not have to write out your situation "on" your car and the lack of text may be easier for you to avoid legal involvement.
Though this is only an action of revenge. A lawyer might be the best route.
Escudo, '93, 4 door, 16v, 4 spd Auto trans, 4WD, Auto locking hubs
1994 Isuzu Pickup 2wd 5 speed short bed