Yes, interesting history to this. When the tax bands were announced all cars in that emission band were due to pay the higher rate regardless of date of manufacture. However, under pressure from various motoring organisations it was felt that this was unfair to current owners so the tax was lowered to half of the new rate. This was supposed to be a temporary thing and as far as I'm aware isn't set in stone, although the number of cars in this bracket will be quite low and going down each and every year so I don't think it'll change now.
Pete
Interesting Pete, never knew that it wasn't set in stone so to speak.