It always amazes me when I see people cycling on busy town/city roads wearing headphones (presumably listening to music) - I need ALL my senses when cycling, especially in towns/cities.
Never mind that, have you seen how many drive around with a petrol engine making a godawful racket right in front of them and windows blocking the external noise?
I'm so glad you wrote that, saved me the job.
I cycle with headphones on. They are open backed headphones and I'm usually listening to radio 4 or a podcast. I find listening to something like this helps me concentrate and not get lost in thought. I've had people tell me off for this. I had some old woman give me an inquisition when I stopped out side a chippy. And was taking the headphones off. She said something to me. I uncovered my ears and said "pardon?" "This is why you shouldn't ride with headphones you can't hear what I was saying" "but I knew you were talking. I don't need to be able to tell it's a flat 6 engine in the car behind me, just to know the car is there. I can do that even over the sound of radio4" I then went to get my fish n chips. She didn't like the youngen talking back, and hurrrumphed off...
But what I said to her stands. I can hear quite a bit even with music on my headphones, it's enough to know the vehicles are there. And for large vehicles I can often feel the vibration rather than hear them.
But back to mirrors.
My immediate thought is "oh do go away" but then I thought about it some more, and conclude, that like hivi, and helmets, and bike to car transponders and all the other bollocks people spout about bike safety, it's trying to solve the wrong problem the wrong way.
You're worried about cars driving into the back of you? Fine. Get the cars out of the cycle lanes. Problem solved. Oh and while you're at it, fix the law so there is presumed liability for the driver. That's going to have a much bigger impact than some tin foil on a stick cluttering up my handlebars.
Oh, and as for helmets. Their sole purpose for 99% of riders is to protect you from the judgement of fellow road users. And I say that as one of the half dozen people who commutes through Amsterdam wearing a helmet.
If you want to take one measure to improve the outcome of you coming off your bike, get a cheap €10 set of gloves. You'll get far more use out of them than any other safety crap people suggest. After an afternoon spent picking gravel out of the palm of your hands, the sacrificial skin layer gloves provide is well worth it. If I had to choose between helmet and gloves. I'd choose gloves every time.
End rant.
J