That largely depends on the price of gas, seeing that the KIA gets about 15 more MPG.
I ride a motorcycle, so I have no idea. . .o-0
If you want thoughts on the D80, here are mine:
Lightweight (if you're not a complete weakling), has a sturdy construction - even if it is made out of plastic, and looks sexy as hell. There are a ton of buttons and features, with the most used camera controls (ISO control, quality of picture, white balance, exposure settings, and even adjusting custom colors) no more than a button or two away.
The menu, and in-camera functions are so much better than my previous D50, you can even do slight photo adjustments to the pictures in-camera including cropping and lighting, and save the resultant image as a seperate photo (so as not to destroy the original).
Other than that, I would check out Nikonians.com or DPReview.com and read the users reviews if you want a wide range of opinions on the camera. Thom Hogan also has a review of both the D80 and D40/x and comes to the conclusion that they are virtually the same. So really what it all comes down to, is whose opinion you will put more stock in.