According to Megan Fox, she was attending a Linkin Park concert and when it was over, the band met her personally and stated that they heard about the live-action "Transformers" film, and requested whether they could have a song of theirs in the film, and thus "What I've Done" appears in the closing credits.
Peter Cullen, the original voice of Optimus Prime, described reprising the role as "slipping into an old pair of very comfortable shoes that you haven't worn for a while," and was grateful to the fans for wanting and bringing him back.
(at around 40 mins) For the scene where Scorponok bursts out of the sand right on the heels of the soldiers, the effect was achieved by detonating a primer cord under the sand. The explosions would be in close proximity, and very dangerous to the actors in the scene, so before the scene was shot, Michael Bay told the actors to run and keep running no matter what happens, or else they could seriously be injured or, even worse, killed. As a result, the look of panic on the actors' faces as they flee from Scorponok in this scene, is one hundred percent genuine.
To keep the film realistic and under budget, the U.S. Department of Defense provided their support towards the film's production, the largest project they have assisted since "Black Hawk Down (2001)." The military provided their vehicles as the alternate modes of the Decepticons Starscream and Bonecrusher. They also allowed their F-22 and CV-22 aircraft to be filmed, the first time these planes have been seen in a feature film since "Hulk (2003)." Soldiers served as extras, and authentic uniforms were provided for the actors. In return for the favor, the filmmakers provided an advance screening of the film to the soldiers, free of charge.
(at around 1h 45 mins) The Decepticons were to have more dialogue in the film, but most of their lines were cut out to keep them mysterious (screenwriter Roberto Orci reasoned that the more a villain talks, the less threatening they are). To please the fans, though, Megatron's classic berating of Starscream ("You fail me yet again, Starscream.") was put in the film.