Suspension rattle was what I thought it was - strut mount top failed eventually.
Because of the tiny movement the shock absorber rod continually banged against the underneath of the strut top mount, the rod eventually smashed through the entire assembly and protruded out the other side bashing the bonnet up Guests cannot see images in the messages. Please register to forum by clicking here to see images.
I knew what it was when it eventually failed catastrophically, but near impossible to find beforehand unless pulling the entire suspension apart.
Oh and battery reset didn't fix it.