2002 ML 320.
When it rains i get a gallon of water in both front wheel wells and roof dome light!!!.

Luckily no electrical shorts, started parking it in the garage. Its dry now, want to go after these, the local body shop had no ideas.

Windshield runoff drain? sunroof drain? please guide me as to where to start.
Thanks in advance

 

Sunroof drain hoses are disconnected from plastic elbows somewhere behind dash board. I was reading nice thread on this at benzworld not long ago. Guy was trying to clean them out with wire rod and pushed the elbows right off the hose creating leaks and more trouble then he had to start with. There is no latch or glue on them and sometimes they come of on their own, as I could understand. Common problem on W163 passanger side.
Sunroof ahould have 4 drains, one in each corner. Good luck.
Bernard

 

What mbenz80 stated is correct. Every time it would rain, the passenger floorblood of my ML would accumulate about 1-2" of water. I originally thought I cracked the floorboard since I take the ML offroad, but after checking the underside of the ML numerous times, I never saw any indication of any cracking. So I took it to the dealer and they looked at it for about a week and finally realized it was the drain hoses.