As a follow-up, I can't find any alternative methods of securing the outboard ends of the plinth and therefore, every time I raise the boot lid other than from the centre of the plinth, it moves and twangs back into place alarmingly
Does anybody have any of those interference fit thread cutting fixings that were used originally that I could buy please? I feel sure that, with a little PTFE tape wrapped around the post, I could get a reasonably securely fitted plinth again