Any of you knowledgable lot out there know where I can get a spring clip like this but instead of a self tapping hole one for a 4mm thread or even a captivated nut
Demon Tweeks, Merlin motorsport or Europa spares, perhaps, I think the product you are after are called "Rivnuts" but I may be wrong. Alternately try a local Fixings company (Allfast ), have to check yellow pages for a local one. I have seen what you describe!!