Rogerrambo

I have a leak somewhere, maybe someone can help me out. The drivers side carpet is soaking wet, awhile back I pulled everything back and there was a puddle under the padding. I did some searching and saw the shark fin antenna leaks so I went to the dealership to get it looked at and they wanted $500+ to replace the whole unit for one gasket. I decided I would try to silicone the base of the antenna, its completely sealed. Drivers side is still getting wet, the wet area runs about the width of the door sill all the way across to the center console. I noticed after completely drying everything then sealing the antenna the truck sat in a good rain storm and it wasn't wet so I'm wondering if it only occurs while driving? Are there any other known leak points around the drivers side besides the antenna? Its a 2018 sierra 1500 double cab standard bed.