I don't know that the car sits and warns you constantly. I came home, left the van running, as all the neighbors were getting in so we could all go eat. I went in the house to change into shorts, left the key fob in the pants at home. We drove 12 miles away and was not until I got to the restaurant and parked did I realize I left the fob at home. I think when I got out to lock it. So, we had to wait an hour for another neighbor to come home to get my fob and bring to me. If it had been beeping inside and flashing a message when I had gotten it, I would have gone back in the house to get the fob.