Hi JJ -
Whenever I see a Simpson's reference in a fuel economy discussion, I can't help but think of the Flanders' poor little Metro...
(About to be pursued by the "Homernator"...)
Maude: "Come on, Ned! Move this thing!"
Ned: "
I can't! It's a Geo!"
Anyway, welcome to the site! Sounds like you'll fit right in.
Let us know what you learn from Linear Logic about the ScanGauge not talking to your Fords. It'll probably come up with someone else, and may be helpful for future reference.
-Darin