Jake Wilkinson, a California student, hasn’t been home to Larchmont, New York for any holidays after his biological mother’s death and his father’s remarriage ten months prior. A few days before Christmas Eve, his father, Bob Greiser, learns that Jake has traded in his airline ticket to New York for two tickets to Cabo San Lucas, and he offers to give him a vintage 1957 Porsche 356 if he arrives home by 6:00 PM on Christmas Eve for Christmas dinner. Jake’s girlfriend Allie Henderson, who opposed the Cabo trip, agrees to ride with him back to Larchmont, where her own family also lives.
Jake helps a trio of jocks cheat on their midterm, but their comrade Eddie Taffet, Jake’s rival for Allie’s affections, sabotages the scheme. Eddie and the jocks leave Jake stranded in the California desert wearing a Santa Claus suit, hat, and beard glued to his body. With no way to contact Allie, she reluctantly decides to ride to New York with Eddie.
Jake has three days to reach Larchmont if he wants the car. He stumbles upon Nolan, a simple-minded thief driving stolen kitchen goods toward New York. A police officer named Max pulls them over in Red Cliff, Colorado for speeding, but Jake convinces him that they’re donating the goods to the children’s hospital. Max offers to escort them to the hospital, forcing them to give up the stolen goods.
Seeing the children inspires Nolan to turn around and head west to see his wife, and Max to try to reunite with his own wife, Marjorie, in North Platte, Nebraska. Max asks Jake to accompany him, reasoning that his wife will listen to Santa. Jake, with the help of a traveling band, gets Marjorie to take Max back, and a grateful Max buys Jake a bus ticket to New York.
Meanwhile, Allie and Eddie grow closer. Allie convinces Eddie to stay the night at the Bavarian-themed Edelbruck hotel in Amana, Iowa. They’re caught on TV underneath a sprig of mistletoe. Jake sees them kiss while he’s waiting at the bus station in Nebraska and hatches a plan to convince the bus driver to drop him off at the Bavarian village. Allie explains the misunderstanding to Jake and they make up, until Jake mentions his deal with his father. Upset that Jake seems to care more about the car than about her, Allie storms out and takes Jake’s seat on the bus.
Jake hitches a ride with Eddie until jealousy drives Eddie to eject him near a Wisconsin town. Jake enters a Santa Claus 5K run and wins the prize money to buy an airline ticket home, but learns the town’s mayor uses the prize money to buy food for the impoverished and donates the winnings. Meanwhile, Eddie is arrested after insulting two local police officers and his car is towed.
Tracey, Jake’s younger sister, uses her savings to buy Jake a ticket home, but, prohibited from flying without photo identification, she stows away in a dog kennel on a cargo aircraft. Jake steals a one-horse open sleigh from the local parade and rides to Allie’s house to make up with her. They arrive at Jake’s house at 5:59, and when his father offers the Porsche anyway, Jake refuses, but looks forward to spending the next several holidays at home fixing it up with his father and finally accepting his stepmother. The Wilkinsons and Allie climb into the sleigh and join the parade just as it arrives.
