Everyone always seems to jump from general schemes (road tax, fuel duty) to Orwellian tracking (GPS everywhere). Seems like a simple scheme of mileage tracking and net charge tracking would do. You then have an overall energy use / mile figure that you can use to price each mile so people who buy more efficient cars are rewarded, and then charge by total number of miles, so people who do fewer miles pay less.
It would also be beneficial to incentivize better vehicle choices at the point of sale. Ebikes should be subsidized to the point of being free or nearly so. Other evehicles should be taxed extremely high per pound of mass. A family of four should therefore naturally gravitate toward a compact hatchback over a massive SUV that weighs twice as much like they do today when there is no incentive for getting a smaller vehicle.