Cheers for that @Ewan and @duncancallum.
So what do you do when the Varia says there is something coming up behind you fast?
Currently I only look behind when I am changing road position, usually to get round Cheshire’s large and varied selection of potholes or pulling over to let something past me on a narrow country lane. I just can’t see what I would do different knowing there is something behind me .. crash in to the pavement?
Worst recent experience was when one of those tractors with 4 large wheels (PV67XXX) towing a long trailer with a digger on it, decided it would go past me at 20-30mph on a Shropshire country road where there were some cars parked on both sides. The tyres were weaving around 18” from shoulder … ridiculous.
Apologies for sounding ignorant, I’m just trying to understand what difference a Varia would have made as a decent outlay and something else to keep charged up!