Slovakia-based AeroMobil claims that its two-seat 4.0 model STOL personal aerial vehicle will be ready to enter commercial service in 2023, powered by a conventional gas engine. AeroMobil also is working on an electrically powered vehicle that would have VTOL capability and be suitable for air taxi operations. It had intended hopes to build a full-scale prototype of the four-seat 5.0 model by 2025, but as of December 2020 work on that project had been temporarily suspended.

In early September 2019, AeroMobil revealed plans for a new 6.0 model that it said would be its first true eVTOL aircraft, built solely for flight operations. It classes the 4.0 and 5.0 as "flying cars." The company indicated that it intends to present a scaled model of the new design "within a few months," suggesting that it could be unveiled by late 2019.

The planned performance specifications for the 6.0 do not appear to have been fully defined. The company says it is trying to determine what range and payload to focus on out of the following three bands: 30 km (1 to 2 passengers), 30- to 70 km (2 passengers) and 70 km (four passengers). However, it believes that the market for eVTOL aircraft will not be sufficiently well developed until around 2030 and on this basis it is deferring development plans.

In June 2019, AeroMobil's engineering team achieved a ground test run with the Prodrive 2-liter, 4-cylinder engine that will power the 4.0. The first prototype fitted with this engine was supposed to make a first flight before the end of 2019 and, as of mid-August 2019, the company's engineering team was assembling the wing. The engine generates 300 hp to run a 2,400-rpm direct-drive propeller, supporting projected flight range of around 440 miles (700 km) and speeds of up to 166 mph (260 km/h).

AeroMobil filed a type certification application with the European Union Aviation Safety Agency in December 2018. The 4.0 is due to be certified under EASA's CS23 regulations and separately as an M1 category road vehicle, with the company projecting a 2023 target date for completion.

The larger 5.0 model was still at the concept stage as of August 2019, with one early version of the aircraft built so far and being used to assess various possible configurations for the series production model. It is expected to be powered by a 100-hp Rotax 912 piston aircraft engine.

In July 2019, AeroMobil announced that private investor Omid Vaziri had joined an existing group of backers to take the total amount raised for the company to around $27 million.

In September 2019, the company also reported that it is working with unnamed "leading" automobile manufacturers to develop cabin interiors for its flying cars and eVTOL aircraft. It argued that customer acceptance will not be high if the level of cabin comfort is little better than that available in existing light aircraft. 

In a December 2020 briefing with FutureFlight, AeroMobil CEO Patrick Hessel confirmed that the company had begun flight testing a 4.0 prototype over the summer months. He explained that the model represents extensive improvements from an earlier 3.0 design and is the result of no fewer than 250,000 hours of engineering work and around 10,000 hours of "virtual" and "real" testing, including flights as the company prepares to get a full experimental test certificate. 

According to Hessel, the company is now looking to select partners to supply key components for the production vehicle. Its business plan calls for it to sub-contract final assembly to a contractor. However, flight testing is due to continue to meet the remaining CS-23 certification requirements, with some minor design changes anticipated to optimize performance. During the latest round of flight tests, the 4.0 achieved its top-speed target of 160 mph and an unspecified stall speed. It also demonstrated its ability to take off in just 1,300 feet, its stall speed of around 60 kts (69 mph), and achieved a rate of climb of over 1,200 feet per minute.