Thanks for all the advice and a suggestions, I think I have homed in on the problem. I had a chat with Morgan and my car is missing a plastic insert that sits under the spare wheel. Apparently this insert deflects water that enters between the wheel and body at the top. Without this insert the water runs along a shelf along to where the seat belt is bolted and finds an easy route into the cabin and onto the floor. If I take the spare wheel out and look along inside I can see the seat belt! Waiting now for the plastic insert so fingers cross it solved the problem.
Roger
Plus Four 2021
Blue
Useful information, thank you Roger.
