This site was just recently released: Wheel Envizio, the ultimate online wheel configurator.
You can pick a vehicle, select wheels, adjust the suspension, pick a background, and take a photo.
You can rotate everything in 3D using your mouse. Once you have a configuration that you like, click the VIEW THE FINAL IMAGE button to get a high-quality render of your configuration.
The program has 300+ 3D vehicles and hundreds of wheels. New vehicles are being added weekly.
You need Flash and the Viewpoint plug-in to view it. You can download the Viewpoint plug in here.
Actual renders from the program: