In the tradition of 1999's "American Pie" and Judd Apatow's repertoire, "Sex Drive" is a raunch-packed comedy, funny as all get-out, but underneath that politically-incorrect hilarity is a big softy. Writer-director Sean Anders and co-scribe John Morris (both making their feature debuts) display an exuberance for their material. They may not always make the right choice—tonally, the picture is all over the map, outrageous one moment, then purely outlandish, and then sweet and back again—but there is a mind behind their methods that proves they weren't out to simply make throwaway teen-movie fodder.

Working part-time at Señor Donut and prepping for college in the fall, 18-year-old Ian (Josh Zuckerman) is an average kid whose inability to take chances has left him very unlucky in the ways of love. When he has second thoughts about traveling nine hours away, from his home in the suburbs of Chicago to Knoxville, Tennessee, to finally hookup with a girl he has met online, his experienced buddy Lance (Clark Duke) talks him into going through with it and offers to tag along. With Ian's lifelong best friend Felicia (Amanda Crew) also joining in—she is under the impression that they are going to visit Ian's cancer-stricken grandmother—they steal Ian's boneheaded older brother Rex's vintage 1969 GTO and take to the open road. Comic misadventures and a heaping of soul-searching on everyone's part naturally ensue.

If the image of a girl cocking her leg and peeing in a car's radiator while a shocked family drives by doesn't sound amusing, or the sight of Amish people getting wasted and throwing up while cheerfully yelling, "Rumspringa!" comes off as personally offensive, then "Sex Drive" might not be the film for you. For viewers with a more open-minded sense of humor, this is one of the more consistently funny films of the year. Director Sean Anders goes the extra mile, doing anything he can think of to get a laugh and succeeding most of the time. Comic ideas that initially appear off-putting, as when Ian accidentally runs over an opossum and opts to put it out of its misery with a tire iron, surpass bad taste and become hilarious through Anders' clever tweaking of such a circumstance. Other scenes, like the heart-rending story an older inmate (Marianne Muellerleile) tells Felicia when the trio get arrested, start off so seriously that all the viewer has to do is smilingly wait and giggle in anticipation for the priceless punchline that is clearly about to occur.

As with any comedy, not every gag works—when Ian is accosted by a penis peaking through a hole in his bathroom stall, it comes off as a tired joke told too many times before (i.e. 2000's "Scary Movie," 2002's "The Sweetest Thing," 2006's "Another Gay Movie")—but even in these few instances, the film's sprightly pacing is such that it doesn't bring things down. With that said, less would have definitely been more when it comes to the screen time of Rex, a stereotypical, almost barbaric buffoon of an older brother, and the outcome of a side relationship between Lance and cute Amish girl Mary (Alice Greczyn) strains believability. These excesses would have done well to be excised, though, again, they do not get in the way of the heart of the story.

As the madcap romp of three friends letting loose and discovering what (and who) they want along the way, "Sex Drive" rings true and is always entertaining. The close friendship between Ian and Felicia that could potentially be leading to more is gentle, warm and on occasion appropriately uncomfortable. Josh Zuckerman (2004's "Surviving Christmas") is an inviting, adorable presence as Ian, a young man who isn't keen on his virginal status but comes to realize he would rather share the experience with someone he genuinely cares for. As the feisty Felicia, Amanda Crew (2006's "Final Destination 3") has star charisma to spare and a winning personality that would make anyone fall for her.

Rounding out the threesome of leads, Clark Duke (of the hit web series "Clark and Michael") shows real promise as Lance. In a lesser, more streamlined project, the unconventional, somewhat geeky-looking Duke would be placed in the role of a socially awkward misfit. In a nice change of pace, Duke's Lance is actually respectful, smooth with the opposite sex, and has women falling at his feet. As the overbearing Rex, James Marsden (2008's "27 Dresses") is a product of a different movie. Marsden makes it his own, but the role is over-the-top and rather annoying in comparison to the charms of the rest of the movie. Finally, Katrina Bowden (TV's "30 Rock") is a delight with a twist as Ms. Tasty, the dream girl Ian is traveling to meet in Knoxville.

A favorable cross between 1985's "The Sure Thing" and 2000's "Road Trip," "Sex Drive" is raucous, thoughtful and romantic in nearly equal measure. Boasting an eclectic soundtrack hailing from multiple decades—MGMT, Donovan, The Flys, REO Speedwagon and Fall Out Boy (the latter band making a cameo) all get playtime—the film isn't overly deep, but it's a truly fun time. For audiences welcoming of an R-rated brand of humor that earns its fair share of grins and guffaws, "Sex Drive" is a teen comedy pulled off with unusual flair.