When his car is
clamped, David visits a peculiar "Car Rental Company" where he is given the only model of car offered, a
1994 Saturn SL with a special
GPS. Driving to a friend's wedding, David is introduced to Sarah, who is uninterested in marriage or relationships, while David, who emigrated from Ireland as a teenager, reveals his childhood dream was becoming a husband and father. David declines to dance with Sarah, and she spends the night with someone else. Driving home, the GPS directs David to a rest stop
Burger King where he runs into Sarah. Despite their flirtation, she remains pessimistic about relationships. Ready to go their separate ways, they discover they both rented cars from the unusual company. When Sarah's car refuses to start, David's GPS instructs him to pick her up, and they set off on their journey together. The GPS guides them to their first stop, a mysterious door in the woods. Stepping through, they find themselves in a lighthouse in Canada David had once visited. They return to the car and reach another strange door which Sarah recognizes as the back entrance to her favorite art museum. Inside, they explore the paintings she often viewed with her mother who died when she was in college. Back in the car, Sarah remembers an enjoyable road trip with her estranged father. Their next destination is a greenhouse where they find the doors to David's high school. Inside, he relives the day he starred in the school production of
How to Succeed in Business Without Really Trying, with Sarah and his parents in the audience. He confesses his feelings for a costar and relives her rejection, but derails the show by confronting her onstage with hard truths about the future. Sarah joins the musical number instead, as the entire auditorium sings the pair of them on their way. Driving into the night, Sarah urges David not to pursue her. The car suddenly stops and they find themselves in a
black box theater displaying the doors to a hospital. Sarah confronts her guilt at sleeping with her college professor instead of being with her mother on the night she died at the hospital alone. While Sarah grieves at her mother's bedside, David comforts his own father who is anxious about the premature birth of his son. Driving off with presents from the gift shop, Sarah changes clothes in the backseat as David reveals his mother briefly left the family when he was a child. They agree that life can feel too short. At a mountain overlook where they gaze out over the entire planet, David and Sarah imagine having gone to the wedding together, and share a kiss. They arrive at a roadside billboard with a door in it leading to a café. David's former fiancée confronts him, demanding an explanation for his ending of their engagement. Sarah faces an ex-boyfriend she suddenly abandoned. Each is forced to admit their romantic failings. They return to the road only to hit a deer but escape unharmed while the car is damaged. Sarah suggests they end the journey before they can hurt each other. David tells her he loves her, but she insists they are only experiencing a fantasy. They spend a lonely night at the nearby Timely Inn while the car is fixed. David drops Sarah off at her car and they part ways, but are each taken to their childhood homes. As his own father, David comforts his fifteen-year-old self, while Sarah relives a happy night with her mother as a twelve-year-old. David returns the car, amusing the Cashier and Mechanic by suggesting they are matching customers with their soulmates. Changing her mind, Sarah arrives at David's address and declares that she loves him. They kiss, and walk together through the front door. ==Cast==