Make your own:  http://www.makestickers.com/

I used them before and can offer a personal recommendation.

2008/10/16 Tabe Johnson <greentabe-vanagon@yahoo.com>:
> I think the "Never get behind a VW Bus" bumper sticker is pretty funny.  I was going to get one made up, but the per-sticker cost goes way down the more they make.  Would anyone else pay $5, shipped,  for a sticker like that?  If so I'll order a bunch.  (white letters on black background)
>
> Please Pmail me if you're in -- no need to clutter the list with responses.
>
> tabe johnson/87 westy
>

--
Chris S.
Disclaimer: "Death and serious injury may occur"