I'm one of the big defenders of appearance mods and personal expression when it is quality work. I'm still not convinced this is actually being done, but it is not exactly appealing to be polite.
I'm assuming that's a 97-03 GP bodykit that was just attached to that GP. The wing just doesn't look like a real product that would be sold. Looks like it was thrown together for "funny" pics. As others stated, that rear is WAY too large for the earlier gen GP and does not suit it. The spoiler in no way flows or functions.
If anything if you want to upgrade your GP, I would update it with GP parts from other available models of that generation. Louvered hood, fender flares/cladding, TGP parts, fascias, etc. Obviously, the biggest and most immediately noticable mod you can do is a good set of wheels/tires. Hell, even the 16 x 8 black crosslace wheels would look nice on it. There are a few actual bodykits available for those GPs. I'm not a big fan of them, but would probably work better than attempting to get that to look like it's not out of place.
Good luck with your project and do quality work. It's great to have your personal style, it's quite a different thing to get noticed for the WRONG reasons. I hope some of the suggestions help.