[JRTJH]

No, you won't have to drop the coroplast. There is a 4" hole in the bottom of the convenience center. The sewer hose, electric cord and water hose go up through that hole and connect to the fittings/plugs on the convenience center. You can just run the telephone line through that hole along with all the other utilities. All you should have to do behind the convenience center is drop that "false wall" in the passthrough and access the sub-basement there.

Have you considered asking the dealership to install it? If you do and if they agree (it's only a 10 or 15 minute job) make sure you point out or better yet, mark with some masking tape exactly where you want the interior plug. Otherwise, you may find it on the opposite end of the trailer from where you "thought" they would put it. I'd suggest taking a couple of 6" pieces of masking tape, writing on them, "Telephone plug" and putting one on the convenience center where you want it located and the other on the cabinet/wall (I would suggest cabinet) where you want the interior plug.

If you do it yourself, all you should need to do is drill a hole through the convenience center plastic, mount the plug, connect the interior phone wire to the inside of that plug and then route it through the "sub-basement" behind that panel until you get to where you want it to enter the cabin and drill another hole there, push the wire through and connect the wall jack to those wires. It's a very "tight fit" in the sub-basement, so if you're "scale challenged" you might want to find someone who is less "ball like" and more "tube like" to crawl in the sub-basement.....