In Lost, Michelle Rodriquez character, a former police officer, apparently dies but reappears in visions, dreams, and the "flash sideways."
What if the Fast and Furious franchise actually takes place in the Lost universe, with Letty Ortiz / Ana Lucia Cortez as the connecting link?
Perhaps Dominic Toretto, or Brian O'Conner, or Mr. Nobody is the equivalent of Christian Shepherd, and all of the main cast members are living out an afterlife scenario to prepare them to "move on."
Also, given the franchise's history of killing characters then bringing them back, what if there's going to be a big reveal in which we find out they pretended to kill off an actor? That is, what if Paul Walker shows up in the final film of the franchise? Not CGIed, but for real? Faked his death and went and hid out in the Bahamas for a few years so that the franchise can stage the biggest comeback ever?