ROAD TAX advice required

[(RIP) PLANK]

We have just received a tax reminder for one of our cars registered late in 2002 according to the reminder it has a co2 rating of 230g/km (Grand vitara 2.0 5dr)

The tax is £115 for 6 months or £210 for 12 months

this is the confusing bit:
http://www.parkers.co.uk/cars/road-tax/?deriv=19565
this table says it changing to band K and will untimatley over 2 years rise to £245

now look at the following:
http://www.parkers.co.uk/News/Road-t...o-tax-changes/
this one says it is in band 'L' and will cost £405 based on the 230g/km emissions.

Now I am of the opinion that i am better off buying 12 months now, as if it goes up in March as originaly planned I will benefit from arround 9 months tax at the old rate.

The alternative is to buy 6 months now, save some cash this close to christmas and space out the gap between the tax insurance and mot as they all fall pretty close together

so do I pay for 6 and trust the first table or play it safe and assume the worst and pay for 12

what would you do? :?