In 2018 Musk speculated on the possibility of a tail lift allowing easier access to ground-level, designed using a four-bar linkage.[30] As of late-2018, Tesla was working on two approaches for the van project: either using a bare-bones Mercedes-Benz Sprinter glider chassis, with Tesla then adding electric transmission, battery and electronics;[31] or alternatively designing and manufacturing the complete vehicle to a Tesla design, requiring more time.[31] At that time Musk anticipated a prototype to be ready to show in 2019.[32]