Monster Aqua Problems in Rear

So I find out, after, I buy my car that it was in a flood down here in Annapolis during Hurricane Isabelle. Not a big deal, pretty well cleaned up, runs ok, new motor I suspect, but all in all not bad shape.

Here's the problem though... there's all kinds of stuff in the back trunk area (its a 97 hatch), and the seats are all kinds of funky. The only reason I found this out is because everytime it rains, the spare wheel well turns into a small pond. I can't find the leak! No holes that I can see, all the weatherstripping is in good condition, can't figure it out.

Next week I plan on tearin out the panels to get a better look. But if you've done this, you know it sucks, so...any ideas on where to look? I suspect it's coming in from the passenger side, always seems to be where the carpet in the trunk gets wet first and were the water damage on the cardboard is. If you have had this problem and can help me find the solution without tearing up my trunk, you'd be my hero.

thanks
-wheel

Maybe have a friend get a bucket of water and pour it on the rear sides and back, and go inside and see if you can see it dripping down from anywhere.

I had this problem on myy 99 Coupe. I loosened the 2 bolts hoding the catch for the trunk lid latch and moved it down so the boot closed tighter. you have to really slam it to get it to latch now but there is no leak.
Hope it works for you!