I think the Buick LeSabre was one of the "standard" picture cars The Burbank Studios (now Warner Bros.) used as background cars during that era. Thanks for identifying.

Any thoughts on the ambulance in the first picture?
I was thinking of a customized Ford Club Wagon or a customized 1983 Ford Econoline 350, but I'm not sure. I'm trying it with another angle that shows the whole ambulance here: