Nope the sticker is dated 2006 - and its the original bonnet too, the car was never serviced at a main dealer either and as far as I can see, the only obvious components replaced on the car seem to be the AC condenser, starter and the immediate pipes, the rad also seems to have been out and in to effect this.
Yes, G1/R o the sticker - G1/E (Filthy) in the system!
Car is a 56 plate but has only done 28K miles.
I dont really know if its worth changing the reservoir just for the filter, I would prefer just to do an annual fluid change on it.
Also this car has no discernable 2.2 'hesitation'