Audi took the covers off the long-awaited Q6 E-Tron overnight. The electric compact crossover is a smidgen longer than the Tesla Model Y, and will start sales in the U.S. late this year both in regular and sporty SQ6 guises. A more coupe-like Sportback body style is also planned, but not for the first year of sales. Mercedes-Benz AMG has revealed…