TC wiring location

My truck is srock and only has a 7-pin connector by the hitch. The dealers all want to install a connector in the bed for convenience, but it seems like that might get in the way for non-TC use. I have a buddy who had the connector installed under the bed in the gap between the bed and cab. The dealer I talked to the other day said that's ok, but is a pain when it's raining and muddy.

Where do yall install the plug? Pictures? Opinions after use?