Chappers
Striker
Or Just stop being a bellend. Park elsewhere and when the ambulance moves, put your car back.In all of those situations, none of them are life threatening, and therefore can wait until the lifethreatening situation has finished.
The emergency vehicle, by definition, won't be longer than an hour max. Even if it is life or death, you can go next door and ask them to move it. And unless they're performing CPR, I'd imagine they would. If they are doing CPR, then it might put things into perspective, you asking to move their "van".