So they are useless. My car warns me even if i don't look. Heck, my car not only warns you, it slams on the brakes for you. Scared the heck out of me when it

So they are useless. My car warns me even if i don't look. Heck, my car not only warns you, it slams on the brakes for you. Scared the heck out of me when it happened, but it saved me from hitting something I didn't realize was so close.