Sunroof drains have to be cleared all the way through glass provider to ward off leaks

https://foxtrot-wiki.win/index.php/Head-Up_Display_(HUD)_Windshields:_Repair_and_Replace

Sunroof drains would have to be cleared throughout the time of glass service to steer clear of leaks. Routine maintenance helps to keep interiors dry and odor-loose 12 months-round.