I love my Sportsmobile van, but am currently selling it and working on plans for a new build. One of the best features of a van is that you can access everything without going outside and/or raising a roof or anything like that. I'm thinking of using a full size truck and building a box style expedition camper on the back, after removing the bed. My question for this thread is how to best build a pass through from the cab to the camper. I want it to be completely weather proof, as big as possible and lockable. Any and all thoughts appreciated. Just trying to get some good ideas to solidify my thoughts on how good an idea this undertaking might actually be.