to anyone else considering autocross, check out my Kinko's race numbers.
I printed the number out on Word. They enlarged it and laminated for me.
I trimmed around the edges with skisors. Then I bought a package of these business card magnet things at Staples or Office Depot and they glued right to the back. Total cost was like $20. But just use blue painters tape underneath so that the magnet isn't rubbing on the paint.
