Does any of that matter? Not really. If you're a fan of fast-paced, improbable action, Fast Five delivers the frenzied goods, although you may find yourself twiddling your thumbs between action set pieces.
Thankfully, director Justin Lin stages the action on a grand, pulse-pounding scale, affording us the opportunity to watch a bus do aerial flips, to see high-priced cars being hijacked from a speeding train, and to witness a climactic chase sequence that threatens to destroy half of Rio de Janeiro while maiming nearly every member of the city's police force.
In case you're wondering, all that belongs on the plus side of the movie's ledger.
The series' two franchise players are back: Vin Diesel, who looks like a man constructed entirely from biceps, returns along with Paul Walker, whose all-American looks are marred only by some obligatory stubble. Diesel and Walker play Dominic Toretto and Brian O'Conner, a champion street racer and a former cop who wind up in Brazil after Brian helps spring Dominic from jail.
Jordana Brewster returns as Mia, Dominic's sister and Brian's main squeeze. Brian and Mia don't have much time for squeezing, though. Like everyone else in the movie, they're too busy showing off their muscles, sweating profusely or planning a totally preposterous robbery.
Dwayne Johnson, formerly known as The Rock, constitutes the biggest (as well as bulkiest) addition. Johnson portrays Hobbs, a supercop who's pursuing our heroes. Sporting a goatee, bulging veins and a determined expression, Johnson joins the kick-ass festivities with as much gusto as he can muster.
In typical B-movie fashion, Brian and Dominic assemble a gang to pull off the job, a task that provides the movie with a reason to add a large supporting cast. Chris "Ludacris" Bridges, Tyrese Gibson, Sung Kang, Gal Gadot and Tego Calderon add humor, some of it by way of comic action, notably a bit in which the toilets in a men's room are blown up. Very messy.
If you see the Fast and Furious movies because you love street racing, you may feel short-changed. At one point, Dominic and Paul seek out Rio's street-racing scene, but Lin ignores the race in which they compete.
I won't describe any more of the action because most of the fun involves the surprisingly ingenious ways in which Lin, working from a script by Chris Morgan, piles on the carnage as the movie races through Rio's impoverished favelas and across its sleek downtown.
The roar of the action and the crackle of gunfire tend to drown out the small voice in us that wonders what happened to logic. Oh well, with a movie such as Fast Five, credibility takes a back seat to stunts, grunts, artfully designed mayhem and fake grit.
Fans will want to stay through the end credits for a postscript that Lin has added. The rest of the world should know what it probably already suspects: Fast Five is more product than movie, a pre-summer money machine that probably will rev up the box office before the bigger boys arrive. Think of it as Hollywood stripping down to its T-shirt as it starts to flex its thrill-ride muscles.