Who bought the car?
For those with teenage SK's who have cars:
Which parent bought it? Which pays insurance? Who has the most time?
Does your SK lie about where they are and go back to BM's house?
I think that when my SD is 16 she will goad my DH into buying her a car, and SD will leave here on weekends to "go to friends" or "run errands" and spend the weekend at Dr. Evil's.