Purchased a 2006 GS AWD new - quite a let down from my 1999 GS which I loved. While the car handles well, it initially rode like a truck due in part to the run-flat tires that came with the car (a "standard" option). With new tires, the car rides better - but still nothing like my 1999 GS. I also feel Lexus's quality has slipped. The car has been recalled no less than 4 times and, to this day, still has rattles in the dash and seat belt pillars. The dealership dampened these quite a bit over many visits, but they're still there. (In recent a consumer test, I see one of 2009 GS test models had a dash rattle, telling me Lexus hasn't corrected the problem in 4 model years).
All wheel drive feature and gas mileage (average 21-22 mpg city/highway combined).
Fix the overly complicated HVAC and audio controls which are each split between dash buttons and the touch screen - not only is it not ergonomic, it's dangerous. A touch screen may be great for taking orders at McDonald's but not for making stereo/heating adjustments while traveling at 65 mph.