+100000000000000000.
Which one of you is paying the most tax on fuel though? What about the 20% VAT thats slapped on that too? How about the 4 tyres a year she uses with another 20% VAT on top? Or the extra 2 services every year ........ etc.
Road tax, even at £500 a year, is less than a tenner a week, think of it as a very reasonable parking charge