Warning, this subject is old (5000 days without answer)
bluefever
actually just looked up the movie on imdb and found out the ambulance is a 1973 Cadillac commercial chassis with coach work by Miller Meteor.
bluefever
The (1990)movie ambulance doesn't seem to be on here,I noticed an Aries K,lincoln towncar limo,Toyota Van and of course the "action vehicle" cadillac ambulance,no clue on exact years.But several other cars to be listed i'm sure.