https://arstechnica.com/cars/2017/04...udi-s4-and-s5/

A little over a year ago, we traveled to California to sample the new Audi A4. The car's combination of excellent semi-autonomous driving tech and that Virtual pit really appealed to our inner nerd. But the A4 is meant to sell in volume, a bread-and-butter model never meant to set the heart a-flutter. That job belongs to the S4, a hotter version with an extra hundred horsepower on tap. Together with the closely related S5 coupe, it's starting to arrive on these shores, which is how we found ourselves among the mountain roads of southern California once again.