kung may leaks man dapat may lagusan din sya...
I think trooper has it.. may nakikita akong 2 holes pababa at parang lagusan nga ito ng tubig....but i'm not sure.
if the sunroof/moonroof is OEM for the car.. definitely it has some sort of canal to channel water away.. and to the side out of the car.. but for installed sunroofs.. mostly kasi it banks on the notion na if its closed its tightly sealed. what happens if the tightness is no longer there?.. then you start singing..
maganda yung moonroof/skyroof, pero kung di naman oem , wag na lang at kung bibili ka ng oem para ikabit, mahirap na trabaho yun, i think papalitan mo ang buong bubong ng car mo, gusto mo bang tanggalin ang bubong ng tsikot mo tapos di rin maganda ang salpak, then di mo rin gagamitin dahil ang init sa pinas.. sunroof is for autumn and spring, pero sa puti, pang summer.
i cannot tell you what to do exactly, but in my opinion, it is better to leave your roof as is. sayang, bababa ang value ng car kapag may mga modifications.