hey , no its not the ventialtions grill, and its not much water , but not much is even to much
. u dont see anything because u cannot see the place where its leaking too less space to look ... its behind c-pillar , but not from above!!! there were leaks from above but i finally fix them ... it was the hinge
now im guessing the water must come from wheel arch, dont want to remove the bumper ... did you ever removed your bumper ? dunno how i manage this ... its a shame that such a nice car is leaking that much ... im so dissapointed