i've got a 2000 SE, and i have those. that's where i plan on flush mounting mine this summer. In the better model intrepids, i believe that whole thing becomes a tweeter/speaker (not quite sure, know it's something though)
I have a 2000 R/T which has the speaker in the A-pillar (see pic).
I also have those "pods/housing" in the C-pillars (you should too). When I overhaul my stereo system, I may put a set of 6.5" components in the back (instead of the 6"x9") and put the tweeter in the C-pillar pods/housing. Not sure how much trouble that would be though.