Performance (incl: speed, accel, braking, handling, balance, steering, shifting, control,..)
Style (the looks of the car)
Reliability (this is NOT the same as build quality) - measures design/manuf flaws not cup holder size
Quality - defined here as craftsmanship and use of top of the line materials, also body panel gap size, etc
Price (incl: incentives)
Fuel Efficiency in MPG
Image - what do you want to be seen driving
Use - family hauler, racer, day car, weekend car, summer car
Safety
Comfort - measured as how comfortable YOU feel in a car and not which car is roomier (incl: lumbar, reclining seats, leg room around the strg wheel, etc)
Features - gadgets like DVD Player, heated side mirrors, mirror dimmers, auto-sensing wipers, high-end stereo, iPod connections, etc.
Color
Sport Package availability
Other?
Lastly, do you consider yourself a driving enthusiast or a practical driver?