Originally received an R rating for the use of the word "vagina" but after a petition and without any edits to the movie, the rating was reduced to PG-13.
When Diaz says to Mann, 'What is this high school? Of course, we slept together. We're adults!' This is a nod to 'John Tucker Must Die' which has a very similar plot concept.
When Carly is looking at Amber through the binoculars and talking to Kate she is not wearing any sunglasses. When she starts to run after Amber on the beach she is then wearing sunglasses. When the camera cuts to Amber and then back to Carly, she is not wearing sunglasses again.