The Daytrippers (1996)

Eliza D'Amico's (Hope Davis) seemingly idyllic marriage to Louis (Stanley Tucci) changes dramatically when she discovers what she believes to be a love letter to him from someone else. Going home to her family for comfort, Eliza sets out with her mother (Anne Meara), father (Pat McNamara), sister (Parker Posey) and her sister's boyfriend (Liev Schreiber) in the family car to track down and confront Louis. Always one step behind him, the family learns a lot about each other in the process.