While it may have been a stainless steel-bodied flop as a sportscar, the DeLorean DMC-12 made a better hash of being a time machine in the Back to the Future trilogy, especially with its ability to pivot its wheels and take to the skies.
No doubt, Matthew Riese (a San Franciscan with what appears to be nutty professor credentials of which Doc Emmett Brown would’ve been proud) got tired of waiting for the mass production of hovercars by 2015 that the second film promised and got to work modifying a DeLorean of his own.
Riese was knowledgeable enough to figure out that hoverboards don’t work on water (just ask Marty McFly) and therefore felt the urge to make a DeLorean that does…enter the DeLorean hovercraft.