Received my new Garmin radar tail-light yesterday.
gchappel recommended it in the 'Roadies' thread.
Took it out this morning for the first time and was very pleased with the results.
The red tail-light is incredibly bright...they claim it can be seen up to a mile.
The radar was picking up cars for the initial warning before I could even see them in my mirror.
Easy to install...I bought the bundle which includes the Garmin display. Shows distances by color and audible warning.
https://www.amazon.com/gp/product/B07BSM6XCD/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1