A lot of pickups have the old slide-openable window in the rear of the cab, and plenty of truck campers have an openable window just behind the cab. What advantage can you take of this close relationship, and what are the pitfalls?
While not advocating the idea, some folks do actually "ride" passengers in the camper. Having a way to communicate between camper and cab, and possibly pass snacks forward, could be a plus.
We've heard of other TC owners whose dog's enjoy the truck cab so much, they'd rather sit there in camp as to be with the folks back in the camper. Until some other notion strikes them, they start barking, and TC owners become "doormen" to their "dobermen." Ahem. Simply sliding the window open to allow pooch access back and forth could certainly reduce steps.
Others say they like the idea of pre-heating or pre-cooling the camper while rolling down the highway through the use of the truck's HVAC system.
The snag on all of these options: The "excess" space between the front of the camper and the rear of the pickup cab. Driving at highway speeds and trying to shout over the wind noise could lead to a loss of voice. Directing a jet of warmed cab air to the camper with that "open hole" at say, 40 degrees ambient temperature is a sure looser. And leaving the window open to allow the passage of the pooch during mosquito season suddenly loses its romance.
How do you plug the gap? Adventurous truck camper owners have tried it all. Depending on the size of your pass-through windows, and the gap distance between cab and camper, some have tried using something as simple as a motorcycle intertube. We did hear that one TC owner tried this, and when the combination of unexpected friction on the tube and hot weather expansion of the intertube caused a rather loud explosion, well safe to say the owner nearly had to do a quick bit of laundry.
Others suggest the use of foam rubber, connected to the camper front with double stick velcro for easy removal. Or you could break down and go the commercial route: Called "truck boots" these little inflatable characters fill the gap like squishing a grossly oversized clear donut between the truck and camper. Sold online by pickupspecialties.com, they're made of PVC. Don't know how thick the PVC is, nor how long they last, but it's a thought. We've also seen them for sale on eBay under the key word "truck boot."