Yes, but I honestly don't like car sex very much (too many experiences with my head hitting the seat behind me or my back grinding against the steering wheel; plus, it's really hard to find a comfortable way to put your legs unless you have a really big car). I'd prefer to find a park or a quiet area with lots of trees, or even an alley way, before doing it in his/my car.

Would you ever have sex in your bedroom with your sister, your mother, and a repair man running around the house, knowing they might knock on your door at any minute?