Elon Musk has often shared a vision of future transportation that is as much vertical as horizontal. This has included moving down into the ground with layers of tunnels his Boring Company will gladly dig for the transit planners of the world and up beyond the atmosphere with the promise of rockets to drastically shorten the length of international flights

So it was just a matter of time until the billionaire and pop culture entrepreneurial personality of the century started talking more earnestly about making flying cars.

It's inevitable, really. Musk's two largest companies, Tesla Motors and SpaceX, make electric cars and rockets. Another Musk venture, Solar City, has already merged with Tesla, so how long could it possibly have been until we saw Tesla and SpaceX hardware intermingling a little more closely?

Musk tweeted about a "SpaceX option package" for the next Tesla Roadster in June of last year. The upgrade was described as including about "10 small rocket thrusters arranged seamlessly around car. These rocket engines dramatically improve acceleration, top speed, braking & cornering. Maybe they will even allow a Tesla to fly..."

Musk then hinted even more strongly at the possibility of a flying Tesla this week when he retweeted a GIF of a flying DeLorean from "Back to the Future," saying: "The new Roadster will actually do something like this."

He then went on to describe how small SpaceX air thrusters will be used to essentially turn a Tesla Roadster into a hovercraft or perhaps... something with an even higher vertical range. 

If Musk meets his own deadline (certainly no guarantee there), we could see a flying, or at least hovering Roadster next year.