Ride-hailing companies Uber (UBER 2.62%) and Lyft (LYFT 0.74%) were some of the most highly anticipated tech stock IPOs in recent history -- and they have ultimately been a letdown since making their public debuts during the first half of 2019.

That doesn't mean ridesharing is doomed, though, and investment in transportation technology is still going strong. Case in point: Boeing's (BA -0.78%) Aurora Flight Sciences and Volkswagen's (VWAGY 0.47%) iconic racing brand Porsche announced they will be working together to develop "a concept for a fully electric vertical takeoff and landing vehicle." Here's what Porsche executive Detlev von Platen had to say about it:

Porsche is looking to enhance its scope as a sports car manufacturer by becoming a leading brand for premium mobility. In the longer term, this could mean moving into the third dimension of travel. We are combining the strengths of two leading global companies to address a potential key market segment of the future.

Third dimension? That's referring to movement not just on the road, but in the skies as well. Does that mean you'll be getting a flying license in the near future? Hardly. This concept vehicle is aimed at the ride-hailing and transit industry, so don't get any grand ideas of hurtling through the air in a Porsche-badged flying car anytime soon. Nor does this mean you should rush off and pick up beleaguered Boeing or Volkswagen stock -- the former beat up by the 737 MAX tragedies and the latter because of Dieselgate -- in your brokerage account. 

The Porsche and Boeing flying car concept, cloaked in shadow inside a futuristic looking hangar.

The Porsche/Boeing flying vehicle concept. Image source: Porsche.

The line forming behind the flying car

Boeing and Porsche would certainly like to be trailblazers if flying "cars" are to be a thing, but they're hardly leading the way in this. Most notably, Uber has been working on an air-based transit vehicle and supporting service it is now calling Elevate. 2023 is the slated launch, although it is sure to be in very limited markets. Uber Copter -- just like it sounds, a helicopter "hailing" service -- is also up and running right now.  

There's also a German start-up called Lilium working on building a vertical-takeoff-and-landing "jet." Its first flight already took place earlier this year. Another small German company, called Volocopter, raised investment funds from Volvo and its Chinese parent company Geely Automobile Holdings (GELYF) for a flying taxi. There's also California-based Joby Aviation and Kitty Hawk, the latter of which also signed an agreement with Boeing to work on flight technology.

Why dump money into this?

Boeing especially should have a vested interest here. While mired in controversy at the moment, the aviation leader is taking interest in flight technology through its start-up division and other subsidiaries -- including through Aurora with its Porsche venture. But the space is getting crowded when a market for flying vehicles, flight electrification, and air-based ridesharing is nowhere in sight. So why are companies and institutional investors pouring money into an industry that doesn't even exist yet?  

According to Porsche: "A 2018 study by Porsche Consulting forecasts that the urban air mobility market will pick up speed after 2025. The study also indicates that urban air mobility solutions will transport passengers more quickly and efficiently than current conventional means of terrestrial transport, at a lower cost and with greater flexibility."

Put simply, this whole ride-hailing thing could eventually challenge transportation in ways we haven't seen yet. Moving people around locally in cars is just the beginning. Movement of goods and delivery via autonomous and energy-efficient vehicles is just starting to ramp up. Same goes for mass transit. And the airline industry could also eventually get a run for its money if flight technology advances far enough.

All of that means business amounting to hundreds of billions -- even trillions -- of dollars every year across the globe. Porsche and Boeing want in, even though they don't see things taking off (no pun intended) until 2025 or later. If you're thinking of investing for the flying cars, though, don't. You'll be waiting awhile for some results.