You can make them yourself. Pick the decal size you want, scan it into your computer, and make copies to a single page. You can even put any size in the scanner, and manipulate it to the size you want with your paint or page program. When you have 4 or more that you like, print the page. Go to Micro Mark and get a pack of decal paper. Take one sheet (or more to cover mistakes) and print it on a laser printer at home or at an Office Depot/FEDEX office/other print shop (put your decal paper in the machine instead of the standard paper). You can then use it like any water slide decal. You can even pick any color you want. If you want a white background, you can just use the white paper trimmed to the diameter to fit the wheel cap. Laser printing is not water soluble, so you can put it under the cap lens.