Welcome, craigq!
I just tried my first Smart this summer - a 2005 diesel cabrio. Shockingly ridiculous fuel economy, and I didn't hate the automated gearbox as much as I was expecting to.
Haven't tried a 500 either... have you yet? I think they're a little smaller than I'm willing to go (smaller than my old Firefly, I think).
Whatever you want to know about the Micra, you'll get answers here.
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View my fuel log 2015 Micra S manual: 5.0 L/100 km ... 56.5 mpg (Imp) ... 20.0 km/L ... 47.0 mpg (US) ...