Snooze alarms: Easy to sleep through; can easily be turned off after only a second of listening -- not very effective at getting one out of bed, right?
Car alarms: Impossible to sleep through; unignorable; don't stop ringing until they've gone through all of their 8 lovely "theme and variations"
of sounds. Would make *excellent* clock alarms.
My idea is that even if you push the snooze, the clock car alarm continues ringing until you've heard the whole cycle, so you will probably be awake by then.
Cars--they can have the original snooze alarms. The button to turn them off is accessible to every passerby -- BUT -- to keep it effective as an alarm, cannot be "held in" and the alarm will rego off with additional vibration.