First I have to say, thanks guys for inspiring me with all your creative solutions. MPGuinos are so much fun!
Here's one for the Metro lovers - in dash installation!! Super slick.
You can do it too, if you're not scared of messing up the cluster. Oh BTW- this DOES mess up the cluster, meaning irrevocable damage done. But if you screw it up, the non-tach ones are only 20-30 bucks, don't worry. Go for it!
Super-quick how to:
1)Starting with a Geo Metro instrument cluster, no tach. Mine has no lights in the center. Remove from car.
2) Open the casing, measure, mark, cut, until you have enough room:
3)Doesn't fit yet? Repeat step two......Lather, rinse, repeat.
Should end up like this:
Hope this helps someone.