Looks like the normal SPG/Aero kit to me, but painted to match the body, with the silver detailing strips removed, and with a whale-tail spoiler instead of the normal one.
I like it, but I think it might have looked better if they had left the detailing strips in rear panels.
It's just the Aero bodykit as far as I can tell. This is the car that started my 900 love years ago.
Not all were turbos, there are a few going around where I live with this body kit that are the same N/A version as mine. I've seen them for sale in good condition for ~$3k.