2weeks ago i watched a video of this Riderscan mirror (it's on you tube). I don't usually fit any parts to my bike unless, the add to my comfort or safety. I ordered this mirror and fitted it, it fits, in my case to the screen. First impressions were, it was like watching a video of yourself whilst riding, and was a bit off putting. The idea is that it lets you see in the "blind spots". I already have a small overtaking mirror on my existing rear view mirror. As most of my riding is done on country lanes it wasn't much use, i tried it on Motorways, and found it did not show much in addition to my ordinary mirrors, until, any overtaking vehicle was actually at the side of me which would have been too late to take any avoiding action in any case. Maybe it's early days yet, but at £29.99+pp of £4. i would not say the benefits of it justify the cost

I have wondered about whether these were any use. As you say £30 seems a bit steep. But if it doesn't actually help, then it seems rather pointless.
I've always found that car-type stick on overtaker mirrors can be very effective at letting you see vehicles in your blind spot (ie just about to overtake you on a M-way) - until it falls off anyway.

It will really come into its own once reverse gear equipped bikes and scooters go on sale.

Might be handy for those with neck injuries/ailments

I take the view that anyone who can't turn their head enough to see behind them over either shoulder should not hold a licence to ride/drive on public roads.

That doesn't suprise me GN2 but it wasn't what I had in mind.

Any additional assistance to help spot other vehicles on the road is a bonus in my humble opinion

S anyone seen those new helmets with a built-in rear view mirror, I mean really built into te shell of the helmet and a tri 'rear' view. At first I thought what's that all about but I have seen more detail and I have been trying to imagine how it would be to have one of these whilst I have been riding.

Connected to and in-built on-board video fore and aft this would be a seriously cool piece of kit! They're a tad pricey at the moment (I think around £500) but maybe that's ok for the added benefit, which I suspect it really would be.

Sorry, that's a slight diversion from your mirror story and a tad more than a 30 quid solution!

What''s behind is only important when changing lane.
Any device which distracts attention from looking in front is a bad thing imo.