This video saved me hours of of trying to figure it out for my wife's 2015. The exact same thing. Thank you so much! Must be a drain somewhere underneath it though? If I can't find it, I'll just drill a hole in it as well!
I have 2009 impala the leak is from the cabin filter they sell a water guard that reflex water away from filter hole also on the bottom of both fender you must remove wheel gaurd to clean out crap leaves and stuff
That's not a solution, that's a hack. That drilled out section will eventually rust out completely and routing the water in ways the car was not designed is bad advice.