Leaking 1985 300TD
 

I bought this car on Saturday in Maryland. While I was looking at it, it wasn't raining but started raining during the test drive. Water was coming in around the windshield gasket, and when I got it back to New York, there was a puccle in the floor (a couple of gallons). The door weatherstripping has separated where it was originally glued together., and the car has a sunroof. I need your help. Are there any typical places they leak? Can it be the sunroof drain holes?