Most shots of RoboCop and the police car show him getting out or preparing to get in. Peter Weller didn't fit into the police car in full costume. When he needed to be in the car, he wore the top part of the costume and sat in his underwear. To maintain the illusion that RoboCop wears the entire suit while inside a car, most shots show his robotic feet exiting first.
The RoboCop suit was so hot and heavy that Peter Weller was losing 3 lbs a day from water loss. Eventually, an air conditioner was installed in the suit.
The screenplay had been offered to, and rejected by, virtually every big director in Hollywood before Paul Verhoeven got hold of it. He received it while on holiday in France, and threw it away after reading the first pages, convinced it was just a dumb action movie. After going for a swim, he found his wife Martine reading the script, and told her "Well, that's a piece of shit". However, she had read it all the way through and disagreed, saying that the story was layered with many satirical and allegorical elements, which convinced him to direct the film.
Because the hands of the RoboCop suit were made of foam rubber, the car keys would bounce off of Peter Weller's hand every time he attempted to catch them. The production took up to 50 takes and an entire day's worth of filming before finally getting the shot right.
Realizing that the film was running behind schedule and over budget, director Paul Verhoeven and producer Jon Davison purposely did not film one crucial scene: Officer Murphy's death. When production wrapped, they went back to Los Angeles and grimly informed the execs that Murphy's death had not been filmed. After watching the footage they did film, the execs were so astonished by the aesthetics and performances they gave the filmmakers more money and they filmed the scene in a redecorated warehouse in Los Angeles.
Edward Neumeier: The writer is briefly seen on a photo on the "Wanted" bulletin in the police department, hanging on a non-transparent glass when RoboCop walks behind it. Close inspection of the original prop reveals that the bulletin bears his name as well and that the fictionalized version of Edward Neumeier is charged with fraud and flight to avoid prosecution. Originally, the man catching the LAR Grizzly gun that RoboCop beats out of Leon's hand in the disco was supposed to be his cameo, but he wasn't available at the time of filming.
Paul Verhoeven: wildly gesticulating guy in the dance club immediately after Leon tries to kick RoboCop in the crotch. This remains Verhoeven's only on-screen cameo in his career.
Paul Verhoeven: [in-movie fake commercials] Several fake advertisements are featured throughout the movie: The Family Heart Center (a medical center specializing in artificial heart transplants), Nukem (a futuristic Battleship-like board game), and the 6000 SUX - the primary vehicle that Clarence Boddicker and his gang use. Fake commercials can also be seen in later Verhoeven films such as Total Recall (1990) and Starship Troopers (1997).
Paul Verhoeven: [religious imagery] Verhoeven has stated that he sees the character as a futuristic version of Christ. The gunshot blast to Murphy's hand somewhat harkens to Jesus' hands being nailed to the cross, the bullet to Murphy's head is seen as the Crown of Thorns, and RoboCop is seen walking on water during the final battle at one point. Furthermore, Boddicker's blood at the climax of the film turns the water red, like wine. In another Verhoeven film, Starship Troopers (1997), there's a small but notable example of this. After a serious mistake under his command while at training, Johnny Rico is punished by flogging. Despite the film being released seven years before the latter film, the scene where Rico is flogged bloody is somewhat similar to the scene in The Passion of the Christ (2004), a film about Christ's sacrifice, where Jesus is viciously flogged to the point of Him bleeding heavily.