The Mercedes Simplex concept car, inspired on its original 1903 Mercedes-Simplex, is displayed at the LA Auto Show in Los Angeles, California, U.S. November 20, 2019. (Photo by Lucy Nicholson/Reuters)

A Citroen Aircross concept car is pictured during the media day at the Frankfurt Motor Show (IAA) in Frankfurt, Germany, September 15, 2015. The car show runs through September 27. (Photo by Kai Pfaffenbach/Reuters)

Suzuki's Hanare concept car is displayed during the Tokyo Motor Show, in Tokyo, Japan on October 23, 2019. The 46th Tokyo Motor Show will be op​en​ to the general public from 25 October to 04 November 2019. (Photo by Soe Zeya Tun/Reuters)

The Toyota FCV Plus fuel cell concept car is displayed on media day at the Paris auto show, in Paris, France, September 29, 2016. (Photo by Benoit Tessier/Reuters)

Toyoda Gosei Co Ltd's personal mobility concept airbag car "Flesby" is displayed at the 44th Tokyo Motor Show in Tokyo, Japan, October 28, 2015. (Photo by Yuya Shino/Reuters)

The Mercedes-Benz F015 Luxury in Motion autonomous concept car is shown on stage during the 2015 International Consumer Electronics Show (CES) in Las Vegas, Nevada January 5, 2015. (Photo by Steve Marcus/Reuters)

A three-seater Toyota Kikai concept car is displayed during the 2016 CES trade show in Las Vegas, Nevada January 8, 2016. (Photo by Steve Marcus/Reuters)

The rear of the Chevorlet Chaparral 2X Vision Gran Turismo concept car at its world debut at the Los Angeles Auto Show in California, November 19, 2014. The annual event is open to the public beginning November 21. (Photo by Lucy Nicholson/Reuters)