There's a set of movies that use the same plot, but I couldn't find it in TV Tropes - it's kind of a collection of tropes (The Paolo/Romantic False Lead, This is Not My Girlfriend, etc). This is the plot: a girl is engaged or dating a guy. She goes on a road trip with a different guy (who is abrasive at the beginning), and she winds up with that second guy.
The key point is 2 people who don't like each other are traveling together. So the difficulty with these movies is finding a reason to get these people who in a car together.
Some movies that are like this that come to mind:
-It Happened One Night (1934, the earliest example I can think of)
-The Sure Thing (1985)
-Overnight Delivery (1998)
-Leap Year and Letters to Juliet (both 2010)
-When Harry Met Sally (1989) started with a road trip, too
-French Kiss (1995) and One Fine Day (1996) are more or less this, with some variations