Leaking water somewhere

[04lss]

My gtp is leaking water from somewhere into the passenger floor. I thought it was the sunroof leaking but ive replaced that. Are there any other areas that leak into that area i should look at?

 

[Scottydoggs]

http://www.grandprixforums.net/threads/6961-Water-in-floorboard-(Take-2)-The-Permanent-Fix

if not that, its the heater core.