Cooperman wrote:
How they will be able to fit the 'black boxes' to classic cars with, say, +ve earth electrical systems,
There are only two connections required + and - does not matter what the battery polarity is. The power supply within the unit will be able to cope with anything from 6-42 volts battery voltage.
Everything else is self contained. location, speed, time, duration are all derived from the GPS system. an on-board GSM sim card will transmit the data to a central computer for billing. They could even automate it further by billing you through the GSM service provider like a mobile phone bill.