If U sell a car & they never transfer the ownership & abandon the vehicle 2 yrs later do I owe the impound fee?

Yes, and if you don't pay they will sell the vehicle. So, unless you want the vehicle back, don't worry about it, they just have to send the bill to show that they did everything possible to return it to the proper owner prior to selling it under a "mechanic's lien" for towing and storage. At least that is the way it works where I have lived.