If you have got tax due at the end of the month get online and tax your car before the new rate comes in, just looked on the DVLA website and if i wait till 2morrow i will have to pay more

Cars registered on or after 1st March 2001 which fall into Band F (CO2 emissions 186 and above) will have their annual rate of duty increased by £25.00 for Diesel and Petrol Cars. (I own MY01 WRX = 242G/KM)

Wifes got a Peugeot 107 998cc = 109G/KM
Cars registered on or after 1st March 2001 which fall into Band B (CO2 emissions 101 – 120 g/km) will have their annual rate of duty reduced by £35.00