Guys Is there a way of replacing the middle lap type seat belt on a P38 RR with either an inertia belt or even some kind of harness adaptation to work with the lap belt to make it safer for the occasional trip we need to do with a child sitting in them middle.
I know Exmoor trim do a 3 pt belt for the RR Classic and Defender, so have a look there if you haven't already. It uses the seat back for support, so I have to admit I wasn't happy to use it in the family car though.
Having seen an after market seat (for a camper) that does pass a crash test I don't think a standard seat would hold up, should the worst come to the worst. IIRC they test them to 1.5T.