Anytime the device is removed and then reinstalled, a notification is sent to you stating the time the device was removed, the time it was re-installed, and it will give you a breakdown of how long it was removed.
It's important to note that the alert is sent when the device is reinstalled and not when its initially removed. There is no power source when it is pulled out.
To find this type of alert any time, tap on the blue header at the top of the app, then tap on the picture of the Vehicle. From there you can select 'View History' in the header and see events that are not related to driving habits.