Water on passenger side floor

[ryanm33]

Last night I found my passenger side carpet saturated with water in my 2015 Silverado 1500. I lifted the carpet up and found the underlay soaked and a pool of water in the floor pan. After searching the internet I found this is a common problem with many potential sources. The shark fin antenna, leaking seams behind the front fender, through the firewall, and from under the cowl by the windshield wipers. I don’t think mine is coming from the radio antenna or from behind the fender as it is running straight down the firewall from behind the glove compartments. It is raining steady here today and my truck has not moved and it is a steady stream running from behind the glove box. Does anyone have pictures or a better description of where I should be looking on the firewall or under the wiper cowl?