Del. Code tit. 21, § 6102

No owner of any motor vehicle who is engaged in the business of renting motor vehicles without drivers shall rent a motor vehicle without a driver, otherwise than as a part of a bona fide transaction involving the sale of such motor vehicle, unless the owner has previously notified the Department of the intention to so rent such vehicle and has complied with the requirements as to the showing of financial responsibility as provided in § 2105 [repealed] of this title.