The Porsche 911 used in the opening scene of the film was lent to the production by director Michael Bay, who was already a successful director of TV commercials and music videos.
The film's production was extremely grueling for Michael Bay due to script problems (Bay would later call the screenplay a "piece of shit") and budget limits that often meant Bay would get only a single day to shoot action sequences that would have taken four days of work on more lavishly-funded projects. Bay sacrificed part of his salary so a key sequence during the film's climax wasn't eliminated.
According to Michael Bay on the DVD commentary, he had a fight with Will Smith over the ending. Three days before they shot the ending, Will agreed that he would say "I love you" to Martin Lawrence. The day they were about to shoot the ending, Will changed his mind and didn't want to say it. Michael Bay fought with Will for over a couple of hours about why he should say it. By the end of the fight, in complete frustration, Michael told Will that he didn't care anymore because he only had about 15 minutes to shoot the ending by this time or he didn't have an ending (he wasn't given additional days at the time of filming). When the scene was shot, Will finally says "I love you" to Martin. That shot appears in the final cut.
In the chase scene where the criminals kidnap Julie from Collins Park, they steal a taxi cab. Right after Marcus jumps on top of the cab, you can clearly see a sparkler behind the front fender. This is probably a special effect to simulate sparks from the car bottoming out.
When the car on the bridge is caught in the ethanol explosion, part of it comes crashing back down. A rigging cable attached to it is clearly visible in silhouette against the flames.
Marcus Burnett: Do you see the fuckin' emotion I'm goin' through right now? That means this shit is serious. That means me and this motherfucker's not vibin' right now. That's what that shit means.