Google CD7_CD9.pdf. This is the shop manual for the 94 accord that is almost identical to your 96. Go to the body section and click on interior trim to see how to remove that panel.

Rust can form pretty quickly, so it is reasonable that you can get rust after a few months.

 

Thanks PAhonda, Ill look for that doc to have for future reference.
From last few pics I posted would you think that having the decking panel glued in like that in the window sealant in that area that it would be pretty likely that is the cause of the leak?

 

If it is stuck on the edge, then no. If is sticking through the seal, then yes.

I'd probably line newspaper around the edge of the rear window, then let a garden hose pour down the rear of the car from the roof. Look for the wet spots on the news paper. Also check if that rear deck is wet.

 

The rear deck right under that section that is glued in between the glass an pinchweld is wet underneath. Ill run the hose test tomorrow to see if water is making its way in that spot. The material from the decking looks to be embedded a good bit in the pinchweld but not poking out of the other side where the outside seal is that I can see.