This might get tricky to explain but did you know that car tax rates come DOWN in April 2010 for low emmission cars (<141 g/Km quite a lot of cars); I didn't until now.
This link is the government detail:http://www.direct.gov.uk/en/Motoring/OwningAVehicle/HowToTaxYourVehicle/DG_172916
I have just had a renewal for my car that is in the 128 g/Km band; currently £120 but guess what after April 2010 it drops to £90; but the renewal makes no mention of this!!!!
So here is the tip; if you renew for 6 months at the current higher rate and then get a new tax disc in 6 months it should be at the lower rate so in my case you can save £4.50 overall.
I am a bit annoyed that my renewal does NOT take into account the fact that the rates will drop in April so I feel better that I am getting something back even if it is only £4.50 (after you have added in the 10% surcharge for 6 month tax). I never thought I could come up with a deal against the Government?!!!