The S8 Plus’s twin-turbocharged 4.0-liter V-8 has a sinister yet subdued rumble and rockets the big all-wheel-drive sedan down the road with supercar-like force. The sprint to 60 mph is dismissed in a scant 3.3 seconds, only 0.4 second behind Audi’s own V-10–powered R8 sports car. If you shell out $11,000 for the Dynamic package, the S8’s top-speed limiter doesn’t kick in until a lofty 190 mph—perfect for the autobahn, if not American freeways.