Nonsensical high concept plot ("killer" ambulance drives around snatching up diabetics), ludicrously entertaining dialogue (Red Buttons in particular has some amazing lines), bizarre characterisation (if James Earl Jones ain't chewin' gum he chewin' scenery); basically all the things you can expect from Cohen, cranked up to 11. Meanwhile I'm just shaking my head in disbelief, giddy as a motherfucker.
At one point Eric Roberts (at the height of his mullet game) is being stared down by a couple of punks and goes "What a shitty time to get mugged." so my girlfriend goes "Why is this happening?" and I go "I DON'T KNOW!" with a huge smile on my face.
That about sums up The Ambulance.
The entire thing's on Youtube as well: