What does it mean if I had a dream with my ex girlfriend and I sleeping a car her in the front seat me in the back?

Your dream is telling you that your ex girlfriend is in control, and you are being taken along for a ride. The front seat is the driver's seat. She is making the decisions that effect both of you. You are in the back seat, which is a passive passenger's position, with no control over where you are taken. You're not even "riding shotgun." In fact, you are so passive you are even asleep! I think your dream is telling you to wake up and get some control over your own life.