Wire routing

Anyone know of a good place to run a wire through the back of the cab?
I have a cell booster antenna on my roof I need to route to the inside of the cab. I'm trying to avoid drilling holes. All my previous trucks had unused grommets on the back side of the cab from the factory for upfitters to use. All I see on this truck are the little flappy vent things between the cab and the bed, maybe theres something I missed?

 

There’s rubber grommets on the underside of the cab that are big enough to fit decent wire through. I think there’s some near the back of the driver and passenger seats

 

Yeah I saw those, was trying to avoid poking holes in anything on the bottom as we do go through some deepish water crossings sometimes. But I could just goop it up with some RTV I suppose.

 

Yeah use some RTV and it should be fine

 

There are definitely under-cab plugged holes by the seats that may or may not be used. Tailgate remote lock uses the passenger side one.