I got mine made by m0nk3y. He works at a sign shop and cut the vinyl on a plotter and laid it out on magnetic sheet for me. I cut the numbers out.

I'm sure he could do up a rectangular layout with numbers and class in no time.

Solotime also has a very good reputation. My next set will probably come from them as they have static cling and low tack vinyl numbers that work on fiberglass cars. http://www.solotime.com/