I would suggest one of these...
Buick Lucerne
Northstar V-8, Heated/Cooled Seats, Navigation, and a slick interior IMO
Acura TL
Personally my favorite Acura offering
Mercedes-Benz C Class
Sadly it seems to be you really want some type of performance oriented car, when that SHOULDN'T be your goal. I can tell you if my company allotted me 600$ a month I would be riding in style...