My MicroCar love affair was a Chevy Sprint. No radio, no A/C, manual trans, 3 cyl carburated engine. 48mpg highway at 70+ mph, over 50mpg in the slow lane. I really enjoyed getting up on three wheels going around corners, but passengers were often less enthusiastic. I'm 6'1" and I fit better in a Sprint than a Corvette.
I actually made money by driving it. You could take the standard IRS deduction per mile for work related trips, and going to night school for classes related to my business. IIRC, every mile I drove put about ten cents in the bank including purchase and maintenance.
But to be honest, I'm no longer in the market for such a car. I work 3 miles from home, and really don't drive far enough (other than major trips) for an economy car to pay for itself.