would not replace my mirror with it but add it to my safety features
here are some points on how it works
it should pick up anything approaching you from behind i think
if i walk behind the bike it goes off
so my hope is, bikes, horses, people, mtn lions, bears etc lol
it ignores anything that passes you coming from the front
it beeps when a car gets in range
if the car is going fast it beeps fast a couple of times to alert you
i was not pleased with the mounts that come with it
they are only for seat posts which is useless if you run rear bags on the bikes
there are not many aftermarket options for mounting which was disappointing
but there are a few
very surprised k-edge has not stepped up here and filled this void...
i have a bag with a light strap on it and was able to put one of the seat post mounts on it and have the varia ride horizontal
garmin says it wont pick up right this way but i found several referances online of people doing that and saying it worked fine
seems to be working great
i found this and should be able to put it vertical now
Amazon.com: Garmin Bike mount, quick release, quarter turn
smile.amazon.com
also picked up a k-edge gravity top mount and think it could be bolted to my rack
not sure if i will do that or not
when it is on the bag i can look back and see it
if i put on the rack will lose the ability to see it
it is not cheap and does not come with a catch strap like it should...
the mount seems solid in the locking but still
it does beep twice if it loses connection- like walked to far from the bike
but would prefer it goes crazy beeping so if it fell off the bike you would know right away...
it would annoy me to some extent if i was on regular roads and it was going off all the time, but i have mine turned all the way up for sound and it is loud
there are adjustments/settings for all this
i have not seen the ones with displays in person, you can buy a display later so i started with the new 515 bluetooth device and figured i would upgrade my gps if i wanted a display, so far do not feel i need it
you can also use your phone as the display and ride gps app works with it too
the displays show how far, fast the car is etc
hope this helps some