Audi’s A6 family offers a broad range of midsize luxury car options. The base model A6 is a staid, tepid and sensible German banker’s sedan; The range-topping RS 6 Avant is a raucous 591-horsepower high-performance wagon that breathes hot fire. Slotting between them in performance, price and hotness is the S6.I tested the Audi S6 at home in Michigan for a week, much of it spent carting around my kids to various weekend activities while my wife went to
