Fast Five is the fifth movie in the The Fast and the Furious franchise, but I only saw numbers 1& 2, and I had no trouble keeping up. Among the elements Fast Five promises, a labyrinthine plot is not one of them. If you're looking for a fast paced movie that allows you to turn off half of your brain (or more) for two hours, I recommend Fast Five.
Two additional notes. First, the plot of the movie is pure caper. I remember reading apocryphal mentions a few years ago of a sequel to The Italian Job to be called The Brazilian Job. I wonder if someone appropriated the plot of the never-to-be-made Italian Job sequel for Fast Five. The two movies parallel each other in many regards, but that may just be a function of the caper movie genre.
Next, Elsa Pataky has a supporting role as a cop from Rio. Well known in her native Espana, she's only done a few projects in English, including Snakes on a Plane. Elsa has fabulous screen presence and only a bit of a Spanish accent, so it's hard to believe that American film makers don't employ her more often. Fools.