Reluctant virgin Ian Lafferty (Josh Zuckerman) pins his hopes on popping his cherry with a titillatingly willing internet babe. The trouble is she's 500 miles away. Hooking up with his buddies Lance (Clark Duke) and Felicia (Amanda Crew), he sets off in a borrowed vintage Pontiac GTO to cross country and burn some rubber. Debut writer/director Sean Anders puts comedy pedal to the metal with a top gear breakout performance from Duke as Ian's unlikely luvverman pal and Seth Green as a sardonic Amish mechanic.
The sex drive of college nice guy Ian (Zuckerman) is in wheel spinning overdrive. Trouble is that the availability of willing hotties is in neutral.
However, he thinks he's in pole position when a comely internet hussy - Ms Tasty - promises him a full body MoT if he takes the trip from Chicago to Knoxville 500 miles away.
Pinching his macho brother Rex's classic Pontiac GTO, he heads cross country with his chums Lance (Duke) and Felicia (Crew) along for the ride. His ride.
Writer-director Sean Anders' mainstream debut follows the familiar road trip route - the comedy interstate beloved of fratboy funnymen - but this is no formulaic laugh-a-thon.
For starters he's got a decent script. OK, so it's supercharged with bodily function gags but these aren't ticking over for shock value.
What makes this four star rather than two-stroke is the casting of newcomer Clark Duke - a speccy lardboy - in the sort of role normally reserved for a lantern-jawed all-American girl-baiting hunk.
Lance - who has the look of a straight Alan Carr but the modus operandi of The Fonz - has plenty under the bonnet with a first-past-the-chequered-flag piece of scene-stealing.
Seth Green also rolls up as a sarky Amish motor mechanic who's tasted life outside his religious community and developed a liking for a sexual practice illegal in most states.
The Amish theme also gives the travelling trio a terrific opportunity to let rip at Rumspringa; - when the Amish youth turn 16 and are allowed to experiment with temptations of the flesh. Bacchus would be proud.
It's a keenly enjoyable celebration of teenage insecurity and - for hairy-handed teenage hordes - offers the first chance to see Amish breasts since Harrison Ford clocked Kelly McGillis in Witness.
Let the handbrake off, put your foot down and don't be tempted to pull off.