Shia LaBeouf Compares 'Transformers' Gals Megan Fox, Rosie Huntington-Whiteley

'You went from a biker-machine-shop chick to a woman who's fresh out of college,' LaBeouf tells MTV News about his onscreen romances.

Unless you've been living under a rock and/or have avoided all news related to "Transformers: Dark of the Moon," you're likely well aware that there was much ado about actress Megan Fox leaving the franchise and, subsequently, being replaced with model/first-time actress Rosie Huntington-Whiteley.

With the film in theaters this week, fans have moved beyond guessing about the circumstances that led to the alleged firing and hiring of Fox and Huntington-Whiteley, respectively, and turned their attention to another pressing question: How are the two characters addressed in the film? Specifically, how does one gorgeous girlfriend exit to leave room for a new one? And while we know this is a summer movie full of fantasy, is it really believable that a guy like Sam Witwicky (Shia LaBeouf) could wind up with the likes of Mikaela Banes (Fox) and Carly (Huntington-Whiteley)?

MTV News went straight to the source and enlisted LaBeouf and Huntington-Whiteley to explain the appeal and attraction of their characters, Sam and Carly, and to compare the "Dark of the Moon" relationship to the one between Sam and Mikaela, established in the first two installments.

"The relationship the first time was a person chasing after a woman that he envied out of pure vanity," LaBeouf told us. "He didn't even know her, and he gets burned by it," he added, hinting at a "Dark of the Moon" scene where his character admits to being flat-out dumped by girlfriend #1.

"[In this film], you find him with a woman who's more nurturing, who has a more maternal-type vibe; she's lighter," LaBeouf explained. "You went from a biker-machine-shop chick, which is a totally different sentiment, to a woman who's fresh out of college working for the British embassy as a diplomatic aide; it's a very different personality."

LaBeouf also revealed that before Huntington-Whiteley was cast, he suggested to director Michael Bay that they go for a girl who was the exact opposite of Megan Fox's Mikaela. "I remember pitching to Mike, 'Maybe we should go with a more bookish type,' " he recalled.

"Mike said to me -- and there's two faces to this that are hilarious and insane and also genius, so three sides. I remember him saying to me, 'Shia, we're not going with any bookish anything. This is a summer movie -- we need a summer girl.' To his credit, Mike really understands his audience. There's a certain audience that goes to see these movies that has certain requirements that it needs out of its summer movies."

From Huntington-Whiteley's perspective, her character sees something different in Sam than Mikaela did.

"She is so in love with him. He as a character, he's so funny, Sam, and he has such a great family in the movies," she said. "As the movie goes on, it kind of unfolds that she's had a hard time with her family. She's worked really hard, she's come from England. I think she finds him and he's the first person who adores her, as he should, and she loves that he adores her and they have this really lovely relationship," she explained. "It's a sweet thing. Shia was great to play that, with of course."

Check out everything we've got on "Transformers: Dark of the Moon."

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