My 2004 T-6 is the fifth Volvo I have owned in the past 15 years. Previous versions are the 240,760 Turbo, S70, and a 2002 S-80. The 2004 is clearly the best Volvo and the best car I've owned to date. I bought it with 33/k miles and I currently have 82/k on the car. It looks great and handles very well in all the conditions that Minnesota can throw at a car.
Drop down rear headrest are great. It eliminates blind spots for when my wife drives the car.
Replace the headlight design back to the 2002 version. It cost me 1,400 dollars to replace a front headlight because they don't supply just a removeable lens if broken you have to buy the entire assembly from the dealership. Big cost item.