it's pissible the sunroof water drains , there are 4 of them could be
think of it this way, the 4 points of the sunroof, each have a drain tube
that comes down from inside the track of the sunroof, each drain tip comes out at
the respective corner of the car..if you have water BEHIND the driver's seat,
it is possible the drain tube is clogged from some debris, or detached.
Your other possibility is the top corner of the door where it seals the
rubber door seal. Hinges deteriorate(if older car) seals shrink(if older car)
and water can get in.
Open the sunroof, and take a waterbottle with one of those "trendy" sport
tops to it, that pop out, and shoot some water into each corner of the sunroof,
there is a drain under each side of the windflapper, and to the rear of each of
those. 4 Points of the sunroof.
If the water does not dump out below the A pillar(for the fron drains) on
each side, or under the car towards the rear quarter(when testing the rear
drains) then is is a drain problem.... squeeze the tips of the drain to unclog it,
debris gets in there a lot.... see if it helps...
If the water dumps into the passenger compartment still, it is detached,
because it was once clogged and filled and pulled off.... it happens...
if this is not relevant and water drains appropriately from each corner, then
use some chalk on your door seal, where the seal comes together on the B
pillar, up in the corner, shut your door, open it... do you see chalk on the door?
if not, it's a seal.
If you do, check anyway by pouring water over the door to seal portion and
see if it disturbed the chalk mark....
Also, make sure your roofline gasket is intact... the roof to seal side
sometimes shrinks faster due to UV....and the problem may be the
roofline portion of the door seal...
hope this helps