The level of champagne in Jamie's glass changes up and down.
James' 'The Europeans: A sketch' is one of his shortest novels at about 250 pages, the book that Marian is holding is far larger, probably 400+ pages.
When Jamie and Marian get a flat tire, the briefcase and hat box are in the space in the trunk where the spare tire is normally stored. It is never revealed how they fix the flat and are able to continue their journey.
The bag of frozen peas that Jamie uses to soothe her face features the contemporary Great Value branding that did not exist in 1999.
UNG wasn't the name of the school until 2013 when North Georgia College and State University and Gainesville State College merged, so there wouldn't have been a UNG soccer team in 1999.
Present day vehicles contradict the 1999 story setting, specifically during the many driving scenes.
At the end of the film, the ladies say they are headed to Massachusetts, where lesbians can get married. The movie takes place in 1999, and same-sex marriage did not become legal in Massachusetts until 2004.