Has anyone built a pass through cab to bed? I'm trying to make a third row seat for an '05 quad cab. The seat would be in the bed. My biggest hurdle to overcome is a weather tight seal between the cab and bed. Anyone seen this done before? I want to keep it somewhat simple. The pass though would only be about 18-24 inches wide, not the whole width of the cab, except for the upper portion where the rear widow is. Any ideas?