Last year, because we needed our number on a minimal bumper length, I went to
www.fontstruct.com and built a simple font that when scaled to the right point size will be exactly 4" high and .75 stroke width, but with narrow enough digits to fit nicely on a 2012 minimal bumper length (assuming the short bumper extends to the outside edge of the bumper corner)
See
http://www.chiefdelphi.com/media/papers/2630?
We printed this and handed it to a screen printer business that did all the bumpers (8 x 4digits) for about $50 I think. Best bumper numbers we've ever produced.