I just had some magnets made for my Daimler Ferret. The company did a great job, was very fast, and the prices were more than fair. They offer custom stickers, magnets, and banners as well. I have no affiliation with them but would highly recommend that you check them out. When one was damaged in shipment they sent out a replacement the very next day at no charge to me. It is not often that you get price, quality, and speed all from the same business as well as great customer service. The company's website is:
http://www.stickylife.com/
Here are a couple they did for me. I may order stickers next to see which I like better, but with magnets I can change them easily enough.
CaptMax