Why is my car roof dripping?

If you have a sunroof there are 4 drain holes on the sunroofs inner panel, These drain hole can get plugged and allow water to seep into the cab area. Cleaning the front drain holes are easy. Open the sunroof and you will see one drain hole on either side of the front of the sunroof. Pour some water near the drain hole and see if it drains, you should see water coming out in front of the car. On my 2007 Mercedes GL 450 it comes out by the front of the tires near the radiator. If you see no water under the car you need to clean the drain holes. The rear drain holes are not seeable and they drain behind the rear tire on either side. Cleaning: Compressed air works, sticking a wire down the hole in the front works. The rear drain holes can be cleaned with compressed air, on my car the piping for the rear drains is accessible via the rear access panels near the rear door, on either side. On the rear drain holes you can position the car so pouring water on the tray under the sunroof flows back to the rear holes.