My RS4 V8 was an awesome machine, Ok not the fastest of estates out there, but in all conditions, rain, shine, cold etc, the performance never changed and was useable, and it could confortably take 5 adults and loads of luggage. I averaged about 16-17 mpg over 7000 miles......worth it though.
Throwing an oddball in there, what about a 335D touring? Mine was running 350BHP/520ftlb - Not much out there to keep up with it, although very easy to drive fast so quite boring - So good in fact I had two!