It had a COE cab with the back cut out, then the straight sided part of a panel truck without doors or windows, and then I think it had another cab with doors at the very back.
This isn't it either, but its the one I was trying to find. Its outfitted like a limo on the inside, and appears to be constructed similar to what you descibed. Certainly long enough to be hard to park!
COE Limo Car HaulerThis one was owned by a Portland based trucking company owner. The guy hosted a show every year featuring his own stuff and inviting others. He had died just before this show in '06 and I don't know if the collection remains together or not.