Re: No second hand market
Your car has its meter read periodically - yearly as part of the MoT or maybe monthly. You're charged per mile.
That is actually a very plausible way for them to try.
Obviously I could just disconnect the required cables or overwrite the specific data, but it'd catch most people most of the time... especially if there were spot reads at the roadside every few months.
It miss the real cheese though, which as another poster mentioned will be a time & location component to the charge, but they could phase that in over time as the older cars head for the scrapper.