I recently watched “Airplane!”, and if any of you have seen it before it's pretty funny. Well, there is one part where someone in the control tower is calling ambulance and rescue vehicles to the runway in case of a crash. He calls one set of vehicles, and it shows them going by, and then he calls another set of vehicles, and in the middle of that set is, or what seems to be, the Ecto-1! I even paused the frame to get another look at it.
Now it wasn't really the Ecto-1, as Airplane! was made a few years before Ghostbusters. However, I'm almost positive that car was a '59 Cadillac Ambulance, same model as the Ecto-1, but painted red and without any sirens on it.
Anyway, I just thought that this was an interesting find.