Thanks
@Andy-Mat for suggesting that I use a Oxford Lollipop side reflector. I tried it out for the first time today, and I am happy to report that most drivers did seem to allow me more room than usual. Very good tip!
Shop Oxford Fold Out Safety Reflector - Red. Free delivery and returns on all eligible orders.
www.amazon.co.uk
The product above will only fit on a thin horizontal thin bar. I've fixed it to my rear rack... the only issue I have with this particular incarnation of the idea, is that it isn't resistant enough to wind; doesn't maintain a right angle to the frame. I may make a thin rubber washer using old inner tube, because using a small hose clamp to increase pressure didn't work for that, but it did make the lollipop clamp which attaches to the bike rack secure enough to keep it horizontal . Perhaps I can also roughen that lollipop end at the clamping point with sandpaper, to add a bit of friction, or something. But it's a small fixable niggle.
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