Very comfortable car, smooth ride and quite. Only real gripe that I have with the car is the engine. I've liked the 3.8 in the past, but I think the performance is poor in this car. Could be gearing, but engine seems to run at too low RPMs to effectively change speeds. Engine seems to labor when increasing speed. After it decides to shift down a gear or two, then the performance is there. Mileage is also extremely disappointing. Only get about 25-26 on highway. That is very poor cause my 3.5L (with more horse power) Olds Intrigue got over 30 on highway. City mileage is poor as well in my opinion, I get 18 mpg which includes two miles of stop and go traffic and 8 miles interstate driving.
Bigger, or atleast more efficent engine or better gearing. ABS/ traction control should have been standard in 05. 6 disc CD player should be able to play MP3 as well. Make the Onstar equipment optional, not standard.