The 2006 Cadillac STS-V has an excellent interior and comfort. Tihs car has a powerful engine that pulls hard. Its overall fit and finish is well done.
I love the supercharged engine, seat comfort, quiet cabin, looks, power, smooth shifting transmission, fit and finish, and paint quality.
Add a heads up display, ventilated seats (currently heated only), paddle or steering mounted shifting, and different wheel options (the stock wheels are impossible to clean). Put a LED on the V logo on the dash by the speedo. Add a throaty Crosa or Magnaflow OEM exhaust option like the CTS-V. Give it more horsepower.