I think a sight that might have what you're looking for is the American Racing wheels site (www.americanracing.com
). Try that site, and click on the little link on the bottom that says "Want to see our wheels on your ride? click here" and it'll bring you a new window. You pick the make, model and everything of your car, and then you can pick colors and rims and I think ride height too. It doesn't look realistic, and it only does solid colors but it's easy and it's fast and it's free!
Another thing if you were real serious about realism and accuracy, is House of Kolor puts out a program I think called the Paint Booth. You're supposed to be able to do pretty fancy paint jobs on it on the computer, but it's pretty pricey when I checked it out. I'd rather save the couple hundred bucks and spend it on parts!
A little trick I do is find a picture of the car that I want to change the color/rims/ride height, put my TV set on a blue channel (my vcr has a few channels that are all blue, but any light channel would work) and put the picture up with a sheet of white paper behind it. The static electricity from the tv will hold the paper in place, and you can trace your car without the wheels, and then you can scan it into a computer and print out like a million copies to change height, rim styles, and color. Here's a picture of my current project that I took at the start, and a drawing that i made up that shows what I want to do to it. Give it a try!
[IMG]C:\Documents and Settings\Frank Hanrahan\My Documents\My Pictures\Cars\my cars[/IMG]
[IMG]C:\Documents and Settings\Frank Hanrahan\My Documents\My Pictures\2004-01-08[/IMG]