On an overcast day last September, French race car driver Romain Dumas steered a very strange car up the side of Tianmen Mountain, in the southern Chinese province of Hunan. His fully electric, Volkswagen ID.R prototype — a carbon-fiber rocket with a rear wing like an orca’s tail — was so fast it had caused test drivers to black out, and it howled like a banshee around 99 hairpin turns on a route 6.78 miles long and 4,200 feet high. Seven and a half minutes had passed when Dumas reached Tianmen’s spectacular natural stone arch, “Heaven’s Gate” — a record by almost three minutes. It was the equivalent of climbing San Francisco’s Lombard Street at 54 mph, but with sheer drops rather than carefully-trimmed yards at the shoulders.  Dumas, a veteran of Le Mans and the Paris-Dakar Rally, thought Tianmen was his “most spectacular outing.” But it was more PR than Grand Prix. The ID.4 is the ultra-light, 670-horsepower vanguard of a Volkswagen fleet that the Ge