Nio teases sleek ET7 coupe, to include next-generation power system

Teaser for Nio ET7 conceptNio, one of a handful of Chinese electric carmakers aiming to be Tesla competitors, just teased its next mass-market car, expected to debut at the Shanghai auto show later this month. Its latest car looks set to be a four-door luxury fast-back, perhaps similar to shadows of a car known as the EVE Vision shown in earlier Nio press materials as...