It will obviously be part of the law that the Government have complete access to the data for security reasons, so not only will they know which web sites you visit, the contents of all emails, and if you carry a mobile phone, where you are at anytime, but they will also know your complete driving movements.
Such a black box could be used to give you an annual C02 allowance with you having to buy further credits off those that have not used them to cap C02 emissions from cars. The Government would get their cut from these trades with stamp duty. This would just be an extension of the current EU carbon trading system and would be on top of hiring the road per mile.
1984 is rapidly arriving just 30 years later than expected.
All they need now is to have an id implant at birth (similar to that used on pets) with an EU ID number which is also linked to you NHS / Tax / Passport / Driving Licence Number / Full Personal Details and the ID also as a tattoo as phase one of the next level of control.
Phase 2 would be a personal health monitor, with fines for not doing minimum amounts of exercise etc.
Phase 3 will be you having to speak at all times into a government controlled PC correct word checked speech monitor to stop all offence to third parties and any derogatory remarks about the EU or the EU local government at Westminster. M15 and the Government will of course have full access to the raw speech recording and then is 1984 job done.
I'm sure the directives for these final moves are being considered and planned as I write this.
With taxation always increasing in our lifetime it will reach 100% (like it was in parts of the USSR), we will then be a full command economy run by the EU from Brussels, with them setting what you eat, drink and consume (for your own good health and minimum health car costs of course). This is the logical conclusion of the EU-French socialist model.
Fortunately, I will clear of the EU before all this happens. In the US the opposite is happening with the Tea Party movement being about restoring personal freedom and small Government.