I believe this is the part that you are talking about, its in the middle back by your winshield, It as a pain in the ass to get to, I removed it and cleaned it and the gasket broke so I ended up making my own. The hole thing only took about 15-20 minutes to do.

If you can't find it look at this picture and see if it helps

95 SES Sold 99 SE Sport Sold 99 SVT T-Red Tan Interior. K&N, Magnecors, 19' Theorys, And some audio stuff.