I seem to recall seeing offsets with rotisseries in them, sort of like JR Oylers. The offset is to the back of the cooking chamber.
A quick check, and yes, at least one unit, the American BBQ Systems is out there. I remember seeing one of these in action a couple of years ago and it was a solid cooker and those folks cooked up some good meats.
Whip It Off, Chambers!
"perhaps...but then again...maybe not..."