I have a 1998 Grand Prix se. I was wondering since the factory size speakers in the doors are 5.25, is there enough room to put a spacer in there to fit 6.5" speakers. The door molding look the same from 1998-2001 for sure, but I think 97'-03' might be the same too. I'll post pics of my door in a little while so everyone can see.
You should be able to build a baffle that can give you enough space....but it depends on other things too...like the basket design of the speaker. There's no definite answer, but it's a likely yes.
That depends on what components you're using and how much power you're running. 6.5s usually can take more power, but most people don't run that much to their components for it to matter.