Review on Enhanced Garmin Varia RVR315 - Advanced Cycling Rearview Radar with Visual and Audible Alerts for Vehicles Up to 153 Yards Away by Dwayne Pore

To be fair I've driven the Garmin RVR315 over 150 miles on four separate trips. The device certainly adds another layer of security and mostly lets you know about a vehicle approaching from behind. I'll explain in a moment. It integrates well with my bike GPS (Hammerhead Karoo) and provides visual and audible alerts via Bluetooth. It is most effective in rural areas and can make a car stand out very nicely. There are so many cars in urban areas that you will be overwhelmed with warnings, so distinguishing one car from another is not that useful. Too many beeps to know what's coming. The main problem with Varia is that quite often my bike GPS shows a visual warning (yellow status) WITHOUT an audible warning! Sometimes there is no audible alarm at all! In other cases, only a beep will sound after the vehicle has passed and the warning status will turn green. What's so good about that? I may have a defective device and am planning to send it in for a replacement. I will update this review after trying the replacement. Finally, when Varia is working properly, it alerts you with both an audible and visual warning signal, giving you better road control and more peace of mind. But I don't think this is an inconsistent performance. What's the point without an acoustic signal, that accompanies a visual alarm? Even if it worked perfectly, nothing can replace the good old helmet mirror.