My Garmin Varia just is to alert me somethings coming up from behind. What will you do any different if you were to know there is a car coming at you 30 or even 50 mph faster than another vehicle?
It's only in the very last seconds that you could possibly determine they intend to do you harm and by that time it's probably too late or you crashed on your own because you were too focused on your Varia and not the road ahead.
Varia is not useful if you are in constant traffic of most urban areas, IMO.
Last edited by Iride01; 11-12-21 at 09:08 AM.