As you can see in most of the photos above, many of them had a folding roof that covered all rows of seats, as did open cars, called Tourers (Four doors) or Roadsters (two doors) in Australia and I believe, Touring Cars in USA, so there was no separately covered back seat.
From what I remember reading, Parlour Cars had a fixed roof like a sedan.
In about 1975, Russel Mee, brother of the man who ran Mee's Bus Lines, built up a Charabanc on a 1920's Rugby (I think) truck chassis.
I have my shoulder to the wheel,
my nose to the grindstone,
I've put my best foot forward,
I've put my back into it,
I'm gritting my teeth,
Now I find I can't do any work in this position!
