I found the answer here: http://www.mazdaforum.com/forum/Mazda-mx-3-mazda-mx-6-25/water-leak-17642/
where are the drain holes on the rear part of the sunroof and how do i clear them
Open the sunroof and find the four drain holes. Clear any debris. Blow air inside the drain tubes to find out if there is any blockage. Slide the replacement tubing inside the drain hose.
A bottle brush is perfect for cleaning sunroof drain holes on the Ford Escape. The smaller tip on a two-tip bottle brush can be inserted and then pulled out to clean sunroof drain holes.
Make sure drain tubes are clear so water can run out
does the rear sunroof glass have drain holes
clear drain holes
There are none...i have an 87, short cab and there are no drain holes.
clear drain holes
There are four drains on the factory sunroof. Two in the front corner and two in the rear corners. The front two are the easiest to get to. If you have access to compressed air take a blower with and extended tip and blow air in the front drain holes. Make sure you clear any debris that may have fallen inside your drain channel. The rear two will be able to be cleared if you have access to a piece of 3\8 clear tubbing you can attach to your air blower and repeat the same process as you did for the front. If all fails take it to an aftermarket sunroof company in your area.
stick some thin wire down the holes
Our sunroof leaks after any heavy rain or carwash due to plugging in the sunroof drain holes. From what our service dept. claims, the sunroof does not form a perfectly water tight seal with the roof by design. There are actually tiny drain holes around the perimeter that allow any seepage to drain down through the windshield columns and out near the front tires. It should work unless debris is now plugging those drains.
Don't know if this is the right way to do it but , i unscrewed the plastic trim that runs along the bottom of the sill and cleaned the drain holes out