Porsche is the latest automaker to look seriously at flying taxis, and it's doing so with an aviation giant.

The German automaker on Thursday signed an agreement with Boeing to explore the potential for a flying taxi service, which those in the business refer to as “urban air mobility.”

Imagine near-silent, emission-free aircraft capable of vertical takeoff and landing transporting passengers between major hubs in the world's biggest cities. According to studies, including those conducted by Porsche, there will be sufficient demand for these beyond 2025.

Porsche isn't alone in the race. Rival automakers Daimler, Geely, Hyundai, Toyota, and even fellow Volkswagen Group brand Audi are all exploring the potential. In the case of Audi, Boeing-rival Airbus has been chosen as a partner.

Porsche and Boeing are now working on a concept for a flying taxi. They hope to transform this into a prototype for testing. There's no word on whether the two are looking at autonomous flight capability, though involved in the project is Steve Nordlund, who heads Beoing NeXt, a skunkworks developing methods for the safe co-existence of autonomous and piloted aircraft.

You might be wondering why Porsche is expanding outside of its realm of performance cars. According to the automaker's sales and marketing chief, Detlev von Platen, the long-term future for the brand is being a premium mobility provider, and this could extend to air travel.

“Porsche is looking to enhance its scope as a sports car manufacturer by becoming a leading brand for premium mobility,” he said. “In the longer term, this could mean moving into the third dimension of travel.”