My search for a Hymer is taking shape, but I have a question regarding the S700. Many I've seen online, well practically all of them, have three belted captains chairs and then the side settee behind the driver (LHD). We're a family of 4. My children are 2 and 11. So my question is, can the Hymer take a 4th seatbelt (lap is fine, I suppose) on the settee, or is this not feasible in the UK? The S700 meets out needs perfectly otherwise. Failing this, my preferred choices are 'limited' to the S660/670 models. Any help /advice massively appreciated.