The Stay Puft Marshmallow man doesnt only make an appearance at the end of the movie, he is also seen twice before. In Dana Barrett's apartment, next to the eggs on the counter there is a bag of Stay Puft, and in one of the outdoor scenes an ad for Stay Puft can be seen on one of the buildings.
The Ghostbusters Fire House is located at North Moore, & Varick St. in New York, NY. They have the large white Ghosbuster II sign hanging in their bay.
To promote the film, the Ectomobile was driven around Manhattan prior to the release. In the middle of the film's initial release, to keep interest going, Ivan Reitman had a trailer run, which was basically the commercial the Ghostbusters' use in the movie, but with the 555 number replaced with a 1-800 number, allowing people to call. They got a recorded message of Bill Murray and Dan Aykroyd saying something to the effect of "Hi. We're out catching ghosts right now." They got 1,000 calls per hour, 24 hours a day, for six weeks.
http://www.penguinswithtophats.blogspot.com
From the Upcoming Queue, submitted by Muppetmaker.
John Candy didnt take the role, and it was not because he was dead, that was just for Belushi. Again. Apologies.
http://home.comcast.net/~cartoonistaaron/firehouse01.jpg