My wife and I were out for a drive in the new car after it was stored all winter. She was doing 15 over in a very noticeable car. R3 alerted and she slowed down to PSL with plenty of time to spare. She's talked her way out of worse in the past but unlikely this time. She's taken an interest in learning how to use it and it's paid off. It's great for us both since we tend push it at times. This is our first RD and save. Great feeling and happy we have the unit. Not foolproof, but another layer of protection.