If anything, I think the BSM on my car can be TOO sensitive. Too often I’ll be driving along, even down my street, or a two lane highway, and I’ll see the BSM light up on my mirror.
The way I set up my rear view mirror and exteriors I usually see the car come into view on my side mirrors just as they’re leaving my rear view mirror. I’ve also noticed a car in the side mirror BEFORE the BSM lights up as well.