It's a so-called wet submarine, meaning that it fills with water when submerged, so the driver has to wear a wetsuit and breathe air from a tank. (The dry passenger compartment shown in the movie was a set.) It has no steering wheel or other automobile controls and is instead controlled with levers. The fins on the outside are not retractable, but permanent.
So, the title is false. Or at best, misleading. He is going to take a james bond movie prop and get it wet. He is not going to make [the] "james bond submarine car" a reality. This is somehow increasingly typical of Tesla stories that make it on HN.