What’s not to love about the Ghostbusters? The theme song, the characters, their banter…everything about the movie screamed instant cult classic, and that’s exactly what happened. But although many of us have every word, line and scene memorized, only the true and hardcore fans know of the numerous “secrets” behind the scene stories. Like the frequent ad-libbing and the Ectomobile’s completely different original look. This article highlights five secrets from the original Ghostbusters movie that you can add to your list of random facts.

1. Not Strictly Legal

We all know that Ghostbusters is set in New York City, but in a twist of irony, only a few scenes were actually shot there. In fact, they were lucky to get the few shots they did because the scheduling and crowd control in NYC made it almost impossible to do so. Another issue is that the city doesn’t hand out shooting permits very easily, so the team decided to go rogue and shoot as much as possible wherever they could. As expected, they got in trouble with the local law enforcement, especially while they were filming the montage scene.

2. Stick to the Script or Don’t

In case you didn’t know, most of the Ghostbusters stars were former cast members of Saturday Night Live, who lived and breathed for improv. Naturally, they incorporated their skills from SNL into the film and just about every scene had at least one line that wasn’t part of the script. The actors were constantly putting their own spin on the characters; Bill Murray even said that he decided to act exactly as he would if he found himself in the same situation. Maybe that’s why the film felt so honest and real, especially where he was concerned.

3. Hell on Wheels

When we think of iconic movie cars, the Ectomobile is always at the top of the list right next to Back to the Future’s DeLorean and Knight Rider’s black Pontiac. In the shooting script, the Ectomobile was described as being black, with purple and white strobe lights that gave the vehicle a “purple aura.” That idea was quickly scrapped, as a black vehicle would have been too difficult to film during the night scenes. Eventually, the team settled on the simple yet classic white and red paint job that we know so well.

4. Who You Gonna Call

Ghostbusters is truly the gift that keeps on giving. Even the theme song “Who You Gonna Call” was an instant hit with the public, and peaked at number on the Billboard 100 for three weeks straight. What’s even more impressive is that Ray Parker Jr., who wrote and performed the song, managed to do so in just two days! But things didn’t always go so smoothly for Parker, who was hit with infringement claims by Huey Lewis over his hit song “I Want a New Drug.” The entire ordeal was settled in court and Lewis received an undisclosed amount of money.

5. What’s in a Name?

Ghostbusters… such a simple and straightforward title that almost didn’t happen. Dan Aykroyd, who based the movie on his own personal events including his family’s involvement in law enforcement and frequent dabbling in the occult and spiritualism, knew exactly what he wanted to call the film: Ghost Smashers. Unfortunately, this also happened to be the name of a TV show which led to a legal battle over rights. The team was forced to come up with an alternative name, and after much mulling and bad ideas, they finally hit the jackpot with “Ghostbusters.”