The boyish, Ashton Kutcher-like comedian Andy Samberg made his name in the US posting spoof videos on YouTube; his debut vehicle Hot Rod is a skittish but endearingly silly film from Lorne Michaels' Saturday Night Live stable. Like Death Proof, which only truly zinged in the way Quentin Tarantino wanted it to if you happened to have seen 1970s grindhouse features, Hot Rod might appear semi-incomprehensible to any viewers who've never watched a cheesy 80s sports movie and have only minimal knowledge of old MC Hammer records.
Samberg plays the eponymous hero, an amateur stuntman in a stick-on moustache who putters about the suburbs on a crummy, clapped-out moped; needless to say, his every death-defying leap usually results in physical injury of a sort. His latest mission is to jump a row of school buses to raise money for mocking stepfather Ian McShane's heart transplant: the best gag in the film is that Rod isn't specifically doing it for this brute's health, but just so he can eventually kick pa's ass in a fight.
Akiva Schaffer's direction subscribes to a broad, anything-goes policy: the soundtrack and fashion date from the Reagan era, but the Internet and mobile phones the leads use suggest all this is happening in our own backyard. (Rootlessness is always a problem whenever comedians in their late twenties and thirties try to relive their youth on screen: take the Wayne's World films, where the least convincing aspect was that teenagers in the early 1990s would be excited by Aerosmith and Alice Cooper.)
These SNL offshoots are prone to a certain comic sameyness - like Wayne and Garth, or the clueless nightclubbers played by Will Ferrell and Chris Kattan in A Night at the Roxbury, Rod and his entourage are essentially overgrown kids - and here the hero's hobbydom leads Samberg and Schaffer into the fistfights-and-carcrashes crudity of a Superbad or Jackass movie: more than once, a character goes facefirst into an immovable object, a joke that doesn't get any funnier - or less painful - in the repetition.
There are lulls along the way, and Isla Fisher really ought to move on from having bodily fluids chucked up all over her - she can't do anything especially persuasive or funny with her big speech declaring her love for Rod on the grounds that he hasn't changed (i.e. he's comprehensively failed to grow up) - but Hot Rod nevertheless concludes with a run of very strong gags, most notably the comeuppance of Will Arnett's Andrew McCarthy/Rob Lowe-style yuppie, and the most inspired screen use to date of John Farnham's timelessly inspirational power ballad "You're the Voice".