i dont think they sell one that has only 1 guage location. i think they sell ones that screw onto the a-pillar but i think they look kind of rigged up. you could put a guage in the coin tray like i have seen someone around here do. maybe they will happen along and give you more details.

95 contour se, lots of mods.
http://www.contour.org/carprofile/carprofile.cgi?a=display&uid=00000132