In the scene where Louisa wakes up in the car at the beach, in the shot inside the car, her jeans are torn at the left knee. Subsequent shots show an un-torn pair of jeans.
The image of Ernesto 'Che' Guevara hanging from the rear-view mirror keeps appearing and disappearing during the first part of the road trip, right before it is substituted by the toy rabbit Luisa buys at the township.
After Saba rolls the joint, the leftover marijuana on the Boda magazine on his lap, disappears.
The movie takes place in the summertime - we know this from the boys just having graduated, their girls going off to Europe, the weather, etc. Yet at the wedding near the beginning of the film, the narrator tells us that in a few days the president of Mexico will go to Seattle for the WTO conference - which happened in November.