Water leakage

[kilian tuning]

After removing rust from inside the rear mist bulb housing (bulb didnt work because of the amount of rust on the contact points...) and washing the car, i discovered why it was rusted: there was a fair amount of water coming from the rear mist bulb housing...

Dont know if there has to be a gasket between that whole rear unit and the trunk?
Dont know if this is related to the water which is on bottum of the battery area shown in the pic? (and why it is brown coloured water...?)
http://i1229.photobucket.com/albums/ee469/mavada1/DSC07162.jpg
http://i1229.photobucket.com/albums/ee469/mavada1/DSC07163.jpg
http://i1229.photobucket.com/albums/ee469/mavada1/DSC07165.jpg
http://i1229.photobucket.com/albums/ee469/mavada1/DSC07166.jpg

[hahnmgh63]

What they call the rear foglamp should have a gasket, I believe on each side of the plate is 4B5945395A (javascript:;) I don't see one in ETKA pictured on the right side but once you remove the plate maybe it is there.