Del. Code tit. 21, § 2507

Whenever any motor vehicle for which a title has been issued by the Department, whether such vehicle is registered or unregistered, is removed from this State, through transfer or otherwise, for the purpose of retitling the vehicle in another state, the owner thereof, upon transferring and/or removing such vehicle, shall, in addition to complying with all the other provisions of this chapter, remove the number plates and, if the vehicle is registered, the registration plates therefrom and shall immediately give or send such plates to the Department or an authorized representative thereof, together with a report that such vehicle is to be retitled in another state. If the Department is satisfied that the vehicle is to be removed from this State for the purpose aforesaid, the title to such vehicle shall be canceled.