The best way to water proof is to get new gaskets from the dealership and run a bead of clear silicone around the back of the lamp housing where the gasket makes contact. Set the gasket in place, and run a bead around the cut outs in the body where the gasket makes contact, and install the lamp and gasket assy while the silicone is still wet. If you opt to just reseal your original gaskets, it's easier to see where to put the silicone because of the imprints in the gasket, so putting silicone on each side of the gasket is the best method for used gaskets. If you partially remove the front splash shields, you will see the drain holes for the sun roof, one each side. In the rear, they're up under the bumper cover in the wheel well IIRC.