At a climactic moment in Jordan Brady’s purported romantic comedy, one character flips off another, and director Jonathan Brady chooses to memorialize the event by shooting it in close-up from the recipient’s point of view. The sight of that huge, raised index finger looming in our direction sums up the attitude of the entire movie. “Waking Up in Reno” is offensively bad. Despite the title, if you should find yourself in its presence, stuffing your ears with cotton balls, shutting your eyes and dozing off would be the safest course of action.

The picture utterly wastes the talents of its four well-known leads, but what’s most appalling is the condescending, smarmy attitude it takes toward the low-rent characters they play. Two Arkansas couples–smug car dealer Lonnie Earl Dodd (Billy Bob Thornton) and his unaccountably understanding wife Darlene (Natasha Richardson), along with their closest friends Roy (Patrick Swayze) and Candy (Charlize Theron) Kirkendall–travel by SUV to Nevada on their dream vacation: attending a Monster Truck Rally. We’re supposed to be amused by their redneck antics along the way–quaffing beer on the road, stopping to allow Ray and Candy boisterously to engage in sex (they’re trying to have a baby)–and by their choices once they reach Nevada (the very idea of going to see Tony Orlando, of all people, makes the women salivate). But things go awry after they move into a luxurious hotel suite, when it comes to light that Lonnie Earl and Candy have been having a secret fling. This leads to all sorts of quarreling, door slamming, departures and reconciliations–as well as a weird interlude in which the supposedly lovesick Ray takes up with a prostitute (Penelope Cruz). Everything culminates at the truck show, when Lonnie Earl gets his comeuppance–via the treatment of his precious SUV. (After this catastrophe and “Serving Sara” earlier this year, perhaps filmmakers would be wise to avoid setting the denouements of their epics at such rallies again anytime soon.)

Watching the hayseed bedroom farce that Brent Briscoe and Mark Fauser have constructed from this hoary, crass material play out under Brady’s ham-fisted direction constitutes cruel and inhuman cinematic punishment. There’s not a single moment of wit or charm in the dismal movie, which simultaneously degrades its characters, its stars and its audience. It even manages to turn a funny steak-eating bit from “The Simpsons” into something repulsive. Thornton, scowling and snapping out lines of dialogue with a sneer, has never been duller or less appealing, nor has Swayze, though meant to be sympathetic, been so doltish. The women throw themselves into things, but with embarrassing results. Theron is reduced to doing what amounts to a dopey Daisy May impersonation, all jiggly and sweet, while Richardson is forced to try to convince as a dense, pathetic doormat (though a doormat that turns, of course). It’s truly depressing to see all of them playing brainless, buffoonish trailer-trash–with the emphasis on the trash. And why Cruz allowed herself to be demeaned in the fashion she is here is beyond comprehension. Mention should also be made of the various outfits–the Reno hotel and the AAA Auto Club (whose Triptik is occasionally animated for “humorous” effect) prominent among them–that presumably paid product-placement fees to be included in the picture; they should actually have ponied up some cash to have their names excised, instead.

At another point in “Reno,” a character sagely remarks, “If I could have wiggled my nose like in ‘Bewitched’ and made all this go away, I would have.” It’s a sentiment that every unfortunate soul involved in making the movie would probably echo. It’s a cinch most viewers will.