Grade: D-

This surrealistically awful comedy about a stupidly self-confident, utterly inept wannabe daredevil plays like what it is—a vehicle designed for Will Ferrell but so lame it was passed on even by him (though he stayed on as an executive producer). So instead the picture, one in a seemingly endless stream of flimsy slapstick farces from “Saturday Night Live” head honcho Lorne Michaels, gets the second (or maybe third) team treatment by starring Andy Samberg, a young and, frankly, pretty colorless member of SNL’s current cast.

“Hot Rod” aims to be goofily anarchic, a sort of hip twenty-first century take on Marx Brothers-style nuttiness. But it’s sloppily written, lazily staged and annoyingly dumb, coming across like a home movie slapped together by a bunch of half-addled bar pals. The plot—if one can dignify it with that word—is about Rod Kimble (Samberg), an apparently unemployed young small-town fellow in the Napoleon Dynamite mold. Believing that his late father was a stuntman extraordinaire, Rod wants to follow in his tire tracks. So he rides around on a pathetic little moped, wearing a cape and attempting stunts that always end disastrously. Still, he has a “crew” composed of guys even less brainy than he is—his nerdy half-brother Kevin (Jorma Taccone); Dave (Bill Hader), a gimme-cap-wearing naif who’s got a job at an ice-skating rink; and Rico (Danny McBride), a lug with anger-management issues. At home Rod has a long-suffering mother (Sissy Spacek), but the big influence in his life is his wacko stepfather Frank (Ian McShane), a wild-eyed thug who challenges Rod to fights in the basement to “make him a man.”

What passes for plot development has Frank falling ill and Rod deciding to raise the fifty grand needed for his heart replacement by jumping his bike over fifteen school buses. There’s an obstacle put in his way—besides the need to raise the funds to finance the jump and his own lack of skill, of course—when he learns his father wasn’t what he’s always thought him to be. And there’s a romantic thread involving Rod’s trying to win away Denise (Isla Fisher), the neighbor girl he’s always had a crush on, from her sleazy boyfriend (Will Arnett).

But story isn’t really what “Hot Rod” is all about, and the more conventional material—like that romantic triangle—is tossed off so perfunctorily that it’s almost in short-hand. Instead the script is just an excuse for all sorts of nonsensical bits carelessly thrown together. There are, of course, endless sequences of Rod failing to make jumps and crashing into walls—obviously designed to appeal to the “Jackass” crowd. But they quickly get boring, as do the badly-staged fights between Rod and Frank and other falling-down sequences, most notably a really protracted one in which our hero, following a parody “training” scene in a forest, tumbles down a ridiculously steep mountainside. (“The Simpsons” has done this sort of thing far better.) It might have helped this physical-punishment shtick if Rod suffered some comic injuries along the way—that might at least have allowed for some buildup—but there aren’t any at all, except for one nutty moment when Kimble nearly drowns when doing breathing exercises in a wading pool.

The bulk of the skits, though, are deliberately off-the-wall riffs in the style of internet videos and stoner humor, and anybody not attuned to such stuff will find it very strange indeed. The oddest moments are those between Rod and Kevin; Samberg and Taccone started as colleagues in a comedy group (director Akiva Schaffer was another), and bits like their gung-ho preps prior to Rod’s fights with Frank or a truly weird duet on the words “Cool Beans” (FYI, slang for “very nice!”) will probably leave the uninitiated simply puzzled. But the scenes between Samberg and Hader have a similarly loopy quality. And showing up periodically is an obsessive hanger-on (Chester Tam) whose life seems to consist in gyrating while throwing leaflets at passersby and proclaiming his undying reverence for Rod. We see entirely too much of him.

Through it all Samberg projects an amiably bumptious arrogance, but he doesn’t have much personal magnetism. But his replacing Ferrell must at least account for the movie’s main virtue: the extraordinarily short running-time (83 minutes), which may be explained by the merciful jettisoning of the obligatory Will scene in which the hero strips down to his undies and runs around like a lunatic His three second bananas—Taccone, Hader and McBride—are certainly odd ducks (an impromptu outdoor dance they perform at one point is especially peculiar), but not terribly funny. And Fisher, Arnett and Spacek are almost entirely wasted—with Arnett struggling much too hard to make a mark anyway. Only McShane really breaks out, though not in a very respectable way. His broad caricature of a performance recalls Oliver Reed at his worst.

There’s probably an audience out there for “Hot Rod,” one composed pretty exclusively of young male slackers whose short attention spans and love of supposedly humorous violence the movie caters to. But it’s likely to leave most everyone else cold.