It’s fun (and enlightening) to play with Kelley Blue Book.  For example, I discovered a multi-disc cd player will add $100 to the value of my car, but the presence of air-bags (or lack thereof) seems to have no effect.  I suppose the logic is it’s better to have the ability to quickly adjust your life’s soundtrack to something more ominous-sounding as you careen off the road rather than having something cushion the blow. ~AKH