The idea of the sunroof seal was to keep MOST of the water out, and allow a manageable amount to pass through and down through the drains.

If the drains clog, you will have problems.

Mine both leak a little water in (ends up on ground outside of car.). Just keep your drains clear.

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E