After reading up on the new Edge 520 I noticed the Garmin Bike Radar. The geek in me is suitably impressed, while the more practical engineer side of me thinks the mirror I currently have on my bike glasses will never need charging
Agreed. It's a lovely little piece of technology doing a job that's largely pointless.
I expect that Garmin will sell more than a few of them as birthday presents for rich MAMILs, though, which is the ultimate point.
I can imagine some hearing impaired cyclists finding it useful, but probably not as much as a decent mirror.