Citroen Xsara WRC help required

Hi all

I pulled out my pile of Heller Xsara WRC kits earlier & noticed in a couple of the aftermarket decal/resin packs a replacement rear wing with the vanes, whilst 1 a/m set also has a replacement front bumper with cutouts just ahead of the front wheels. I wasn't aware the Xsara went through an evolution across its career, to include these changes to the wing & bumper.
Can someone offer some info to confirm these changes?

Thanks