The goal I've set will be a tough one: achieving EM hypermiler status, 20% over the rated FE numbers.
As Euro-cycle fuel consumption figures are less realistic than the US EPA figures, it'll be a tough challenge.
All mods will need to be reversible and (at least superficially) legal.
20% better than 47 mpg means 56.4 mpg or 4.17 L/100km consistently.
Spritmonitor.de lists no-one with this kind of FE, the lowest average for non-DrivE Volvo's being 4.36 L/100km.
But then, 100mpg from a Civic hadn't been seen before either