Crash (1996)

Based on the 1973 novel by J. G. Ballard, James and Catherine Ballard are a married couple whose sex life has been reduced to recounting tales of mutual infidelity to turn each other on. One night, James causes a head-on collision with a car carrying Dr. Helen Remington, killing her husband and severely injuring her and himself. Subsequent encounters with each other find that she is oddly sexually aroused by the danger of car accidents and potential accidents, and, he soon falls in with a cult of car-crash fetishists and invites his wife to join in with them.