Noah is looking for an OBD2 device like the Automatic that can give him an alarm if he passes the speed limit, but lets him set the speed. Leo says that the Automatic would alert him if he goes over 70. They were the first to do the iPhone version, and now does Android.
The idea of the Automatic is to teach drivers to be fuel efficient. He can turn the warnings off, but there are other options as well. There is an app called Dash for iOS and Android that can alert him and it will suggest different dongles out there to use. His insurance company may actually have one too and could offer him a discount if he uses it.
(Disclaimer: Automatic is a sponsor)