The 670 horsepower Porsche Cayenne Turbo S E-Hybrid is the quickest SUV to come out of Stuttgart. Charge it up and it can tread lightly on the planet by running solely on electric power. Fast, efficient, practical, luxurious and sporty, this plug-in V8 hybrid is the only vehicle you’ll never need. Just bring a lot of wallet. Tom Voelk checks out a well-equipped Turbo S E-Hybrid Coupe and finds it to be the best sounding hybrid money can buy.