Unless car is not in cruise, it's only blinking BRAKE sign on dash board but not auto applying brake or slowing down car. You manually need to apply for brake. For me, its not worth having a radar system to avoid a collision, I must apply brake like other cars, regardless radar system sitting in front me.

There is device called CMS Collision Mitigation System that you can install any vehicle, that does the same job. I was overwhelmed having radar system in my HONDA CVR, but it's nothing but another CMS device scrap now for me.