Movie memorabilia can collect some steep premiums these days, so few were surprised when a mystery buyer shelled out close to $1 million for the Lotus-based submarine from the 1970s-era James Bond film, "The Spy Who Loved Me."

But the real surprise turns out to be who bought that movie prop—and why. Turns out it was Tesla Motors CEO Elon Musk who snapped up the Lotus body for $989,000 at RM Auctions in London last month. As to why? Musk has confirmed plans to actually turn the prop into a real, working sub car. And, in case you haven't already guessed, his goal is to use a Tesla electric drivetrain.