Is there any way to test the auto dimming function of the mirror(s)?

[Duke_Stratosphere]

I had a vehicle with really bright lights get behind me the other night and it appeared that the inside mirror didn't auto dim. I went into settings and turned it on and off a few times but didn't notice a difference in the glare of the vehicle behind me. Is there a good way to test that the auto dimming function is working?

 

[JPT]

Hold a flash light in the area above the rear view mirror at night, the rear view and one side view mirror should dim. If you have the higher trim model, both side view mirrors will dim. Assuming it is working correctly, and you actually have the function.