Mine is a 2001. I expect the same is probably true for other '97-'03 Grand Prix.
I bought the Spyder tail lights because my OE ones were hazy, cracked, leaking water, blowing bulbs frequently, and I didn't like the OE appearance that much.
When I went to install them, I found it was difficult to get them to go in, and once seated as far as they would go, there was a significant gap below them.
I'd read some people widened the mounting holes in the body, so I tried that on one side, but it made no difference.
Then I looked at the tail light, and the body, and found the problem by where paint had rubbed OFF the body, ONTO the new tail light.
The Spyder tail light is shaped differently than the OE. There's one corner behind a reflector that sticks too far inward, and touches the body.
You can try filing off the corner, but it doesn't appear that would allow enough clearance. The solution seems to be to push in the body where the tail light housing touches.
Up to you how low tech or high tech you want to do this. Smack it with a hammer because nobody will see it, or do more complicated body work.
I have photos but can't upload because my quota is so small, and I don't see a way to delete existing photos. Anybody know what's up with that?
Anyway, without the photos, try putting your Spyders in and rocking them a bit, then remove them and look for the paint marks, and you'll see what I mean. I don't think the mounting holes need to be modified at all.
