My players once planned to turn a fire-truck into an anti-vampire (mostly Red Court) weapon of war. The intent involved having it spray holy water, a Summer Magic powered mirror projecting sunlight on top, a few machineguns firing blessed ammo, and some heavy armoring. The game ended before this quite became a reality but it was a serious plan, with people rolling to acquire the fire-truck and starting to set up the rest. They were going to name it 'Buffy'.
I...had no good arguments why this wasn't both workable and a potentially effective strategy.