Before the roaring race cars took to the Circuit de la Sarthe for the 24 Hours of Le Mans, only the squeal of protesting tires could be heard as Audi’s E-tron, clothed in an R8 skin, took to the track.Audi gave fans a demonstration of its electric sports car before the endurance race began as part of “Le Mans vers le futur.” Vers le futur was a demonstration run specifically for electric