Yes, play a little trick on your teen. After you take a break during your in-vehicle practice session and before he/she gets back into the vehicle, go ahead and reposition their inside rearview mirror so they have no view to the rear.
Say nothing. Wait to see how long it takes for your teen to realize that the mirror is not positioned correctly. Hopefully, you won’t have to wait too long. If you have to wait a bit or your teen does not notice it in the first few minutes, it’s time to pull over and have a discussion about eye movement and checking the rear space.
In fact, if you do this frequently – before your practice session starts, during a break, anytime you and your teen exit the vehicle for a demonstration, etc., your teen is likely to start checking to make sure that the mirror is properly positioned every time he/she gets behind-the-wheel. Isn’t that what you want?
Watch this video about “Surprising your Student by moving the Mirror”. Enjoy!