[bradams]

If, like me, you always want to know how a story turns out, then I am pleased to say I have an ending to my tale.

One thing I did not mention originally is that, because it was my second rear-end shunt in the space of a year, I fitted a rear-facing dashcam at the top of the rear windscreen (insurers love photo evidence). The dashcam is the 'wifi-to-smartphone' type - better than twisting your neck up to view a screen at the top of the tailgate.

You've guessed it! The wifi signal was interfering with the small DAB box right next to it. Move the camera to the bottom of the windscreen, and all is well!