It's been quite a while since I last updated this thread. While the headlight retrofit has not received much attention because of the stupid weather finally getting warm, I HAVE made progress on the Fusion foglight retrofit.
With this being said, GOOD NEWS EVERYONE. Well, at least for us GXP folk. Fusion foglights are more or less a DIRECT swap into the factory foglight position. We even have the ability to retain the OE Fusion foglight bracket to adjust the height of them. It took very very very little work to make these fit.
Now, as far as the output, they are an enormous improvement over the stock foglights (although I did find out they are Koito projectors which was a pleasant surprise.) The color flicker is unreal with the Morimoto 4300k bulbs. It has a thick blue and purple color band that I'm sure looks fantastic to oncoming drivers.
But yes, anyone with a GXP, I HIGHLY suggest swapping these in as it is extremely simple. Also, they can be had for only ~$90 a pair (brand new.)
Hopefully, I've broken new ground in the Grand Prix retrofit world, as well. Any questions about this swap, post here or PM me - I'd be happy to help.