No, if it is registered between March 1 2001 and 23 March 2006, it will be £260.
If it is registered before March 1 2001, it will be £215. Only if it is registered after 23 March 2006 will it be liable for the £445 full amount. This is unlikely, because as far as I know, the changeover to the IS250 was about this time.
It's all listed in that DVLA link posted above...
Cheers for this mate clears it up alot, looks like more reason to get a is200 next :)