I have owned my +4 for the past 4 years and have only just noticed it has a seat belt warning light on the dash, in the warning light cluster. It does not work. There is a cable on the drivers side seat belt receptacle but not on the passenger side. I have taken out the drivers seat and the electrical cable attached to the receptacle has been cut with only about 4 inches of cable remaining. There is no cabling under the seat whatsoever. Is the seat belt warning light an optional extra that needs specifying at build? It’s not that I want a seat belt warning light except if I am meant to have one then I would like it to work.