It'll take more than a DeLorean to get everyone back on board for a fourth installment of Back to the Future. That's the basic message castmembers said during a mini-reunion this weekend at the Fan Expo Boston, according to Movieweb.com.Actor Thomas Wilson – channeling his inner Biff Tannen – said this about a sequel: "Basically, I think America is saying, Come on, they've wrecked every other franchise with bad sequels, why not this one? C'mon, we would watch it until it sucks."Hello, McFly? McFly? He's kidding, he's kidding. Stop being so gullible.Michael J. Fox pointed out the obvious point again: Co-creators Bob Gale and Robert Zemeckis are the "gatekeepers" to the BTTF franchise and have repeatedly said they'll never agree to another installment.Only Christopher "Doc Brown" Lloyd has gone on the record saying he'd be up for another spin.In the meantime, if you have any other questions about the original movie franchise, just consult Wilson's infamous stand-up routine about the movie.