1) I know some people have gotten the ScangaugeII. I saw this one (which is less) and haven't tried to compare side by side:
ScanGaugeE
http://www.amazon.com/dp/B004SK5I46/?tag=m20b7-20
I'm not a mechanic (so I don't need a lot of technical details) though I think I know more than the average...
I finally made up my mind and got over the green (my last car was silver and was in the body shop 3 times before somebody totaled it--none my fault). Sport, MT. At least I'll be visible.
SF Bay Area (any others w/green here?)