for the people trying to get into photoshop, here's a few tips:
first off, layers are yout friends. I haven't done much with cars yet, but i used to take pix of people and I could show what you would look like with died hair and/or colored contacts, a tan, whatever.. same deal really...
it's been a while, but here goes. the exactl commands will be off a bit, but if you look in the menus enough you should find ones that are close.
what you want to do is use the magic wand to select the whole car body, then copy and paste it to a new layer (or something similar) then fill the outline with a color you like. mess around with the transparency of the layer until it looks right on the car.
that is a VERY basic paint job and can really only do basic work. results won't be nearly as good as viking is getting, but it's a strat. the rest comes with just fiddling with the settings and experimenting.
also, always save in the photoshop format and save again in jpg. that way you can go back and change just one layer instead of having to change he whole pic.
i don't have PS7 anymore but i may have to see if i can figure out this Corel Photo-paint we have opn this computer and see what i can throw together.. it isn't as good, but i think i can do something....