Great mileage? King Midget did that 50 years ago Small enough to fit in the back of a Prius . . . a new kind of 'spare.' Bob Wilson
50 mpg... I knew this fella in Texas when I was a younger man... I think he lived in Copperas Cove... anyways... he made a VW Karmen Ghia vert get 50 mpg... nice little car... no air... hell, I got rid of my cars and rode bikes while I was stationed in Texas until my last wreck on an RD Yamaha... and I went back to cars... with air. Mid 70's... Well... unless I was just making a scootercar or something to sell to someone else.
Oh I forgot to add... the Shriner's here in town use the cars in the OP in the parades here locally... they put on a clown/Keystone Cops show with em and do a figure 8 race course on the parade route on a 4 lane street called Fair Oaks Blvd... typically every 4th of July, and sometimes downtown for the christmas parade.