I think the one issue with the newer 4 seaters (I assume it applies to pre-1999 4 seaters as well) is that there isn’t the room to put that new 5 link suspension nor an anti-tramp bar
That would have been pretty good
At one stage Peter Ballard was thinking of a 5 link system for the 4 seater. I don't know if he continued with it though. Demand would be very small I would think.