People gather around a Honda concept car displayed at Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017.

A Toyota Fengchao Way concept car is displayed at the Shanghai Auto Show, during its media day, in Shanghai, China April 19, 2017.

People gather around the Audi e-tron Sportback concept car at the Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017. REUTERS/Aly Song - RTS12VX8

Volkswagen CEO Matthias Mueller attends an event ahead of the Shanghai Auto Show, in Shanghai, China April 18, 2017. Picture taken April 18, 2017.

People gather around the Audi e-tron Sportback concept car at the Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017.

People gather around the Audi e-tron Sportback concept car at the Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017.

A man takes picture of the Hyundai Sonata at the Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017.

A Bentley EXP 12 Speed 6e concept car is presented at an event ahead of the Shanghai Auto Show, in Shanghai, China April 18, 2017. Picture taken April 18, 2017.

A Haval HB-03 Hybrid car from Great Wall Motors is displayed at Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017. REUTERS/Aly Song

A Shanghai Automotive Industry Corp (SAIC) MG car is displayed at the Shanghai Auto Show, during its media day, in Shanghai, China April 19, 2017. REUTERS/Aly Song - RTS12XVA

A Changan Automobile Linmax car is displayed at Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017.

The new Mercedes-Maybach S 680 is seen during an event ahead of the Shanghai Autoshow in Shanghai, China April 18, 2017.

A man cleans the Hyundai ix35 displayed at the Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017.

People gather at the Hyundai booth at the Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017.

Geely unveils its Lynk & Co brand model, the 01 sport utility, at an event ahead of the Shanghai Auto show, in Shanghai, China, April 16, 2017. Picture taken Apirl 16, 2017.

Zotye Auto SR9 is displayed at Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017.

A BMW 5-Series Li car is displayed at the Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017. REUTERS/Aly Song - RTS12XSE

People gather at Nio booth at Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017.

A man cleans interior of a Chevrolet SUV at the Shanghai autoshow during its media day, in Shanghai, China April 19, 2017. REUTERS/Aly Song - RTS12VCC

A Changan Automobile CS55 is displayed at Shanghai Auto Show during its media day, in Shanghai, China April 19, 2017.

People gather around the Nio EP9 electric car displayed, at the Shanghai Auto Show, during its media day, in Shanghai, China April 19, 2017. REUTERS/Aly Song - RTS12XR9