I live out in the boonies myself and do about 30k km a year, I still think tax on fuel makes the most sense!
Its the fairest way, and if you want to put an "environmental" spin on it, it applies too.
All businesses etc could claim it back if required as previously mentioned, I think its madness we don't do it this way!
E92 Interlagos Blue M3 - Current
F10 Sophisto Grey 530d M-Sport - Sold
F21 M135i Estoril Blue - Sold
E92 Sapphire Black 335d M-Sport - Sold
E36 328i SE Low Miler - Sold
E46 Estoril Blue M3 - Sold
E46 Titan Silver 330ci Clubsport - Sold
E36 Cosmos Black 318is - Dead