83 300td water problem

I seem to be collecting water in the rear passenger floor and trunk on the passenger side. I have searched and found that the drains can cause water to pool in this spot but we have not have rain in a week and the carpet is still wet to the touch. There is no rust and the previose owner garaged the car so I want to stop this before I get a real problem. The water getting in the trunk is minimal and does come from a small hole drilled in the plastic liner in the well. It is coming in from underneath. I can't figure out how the water is getting in the back but assume it must be engine compartment/sunroof drains. Any other ideas.? It is real odd that we have not had rain in a week and I still have water in the carpet....