Mercedes Benz repair: sliding roof drains?, roof drains, water leaks

Question
QUESTION: Hello Shane;
I have a 1978 450 slc with water leaks somewhere in the trunk.
I checked the following: trunk seals, antenna gasket, and tail light gaskets, all o.k. Someone suggested the sunroof drains, but I don't have any idea of where to look in the trunk area. Can you please help me with this? Any info is much appreciated.
Dennis in rainy British Columbia.

ANSWER: check all the seals also your rear window. It could be your sunroof seal where does the leak come from the back of the trunk? front reply to this message it is very interesting so a pic would be useful.

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QUESTION: Hello Shane
The leak seems to concentrate and puddle in the left side of the trunk next to the fender/trunk wall. I noticed a small circular hole containing a rubber grommet just below the curve of the fender "bump"
in the trunk, it looks like it was designed for some sort of tubing, and
it is open to the pavement at the bottom. I'm sorry I don't have picture
capability at this time.  Thanks for any and all assistance

Answer
dry it out and spray water down by where the roof and trunk come together check for leaks then that will see if your back window or trunk seal then spray  the antenna grommet and then sliding roof of course you will have to pull out trunk mats etc to isolate the leak and where it is coming from if worse came to worse drill a drain hole in the rubber grommet with a small piece of tube to make it drain automatically