Is there any way that I am entitled to the entire value of the car if both my ex's and my names are on the title and insurance?

You dd not say whether you were married or not. Assuming you were merely a couple, was both names on the vehicle? If so, you must sue him for partition of the asset you jointly own. He may give up the vehicle if a suit is started as it will cost him money to buy you out as well as attorney fees. You can get to own the care in total only if he gives you any interest he might have in the thing. If you are married, you can trade all interest for something you do not wish to keep he might want.

If the vehicle is titled to you, you can start an action ( Claim a nd Delivery) in District Court to regain possession.

Unless you placed a lien on the title you are not entitled any greater right to the car than your ex holds. You have basically given him a half interest in the car. As a co owner you have the right to liquidate your interest in the car. This would be done by filing a lawsuit to divide the co owners interest of the car. Since the car is not capable of being physically divided the court would order it sold and the proceeds divided.