I was able to get two 16 ga wires in a sheath through that channel. But it had to be cleaned out first. There was mud and gunk in there, probably from the precious owner living in Spokane.
I took a panel removing tool and just ran it down the channel a few times. Was surprised how much stuff was in there.
Might give that a try and see if it helps.
Think there's any harm in trimming off that flap that's coming out of the weather stripping that you guys are tucking the wires under? I've had the windshield replaced and I'm thinking that Safelite just did a terrible job and that's why I'm having more issues than you guys. I feel like if I trim that flap, then hit the wiring with some heat shrink tubing and spot glue it down into that seam. Don't think that flap is doing much, but don't want to take a chance on moisture seeping through