Tires wall lettering

Does anybody know a good way to write letters on tires besides using decals?
I've tried using talent & patience but... I hope that there is an easyer way!
Can I find stencils or something in the like?
That's for 1/25
I'm asking the pros.

Source: http://cs.scaleautomag.com/scacs/forums/thread/917489.aspx

George Abecassis Kenny Acheson Andrea de Adamich Philippe Adams