Covered slot next to vent

It’s probably been asked a zillion times but, I can’t find the answer.

What is the covered slot to the left of the center ac vent?

Seems like a clock could have gone there.

 

Mine holds my semi-custom phone holder.


But I think that's for the airbag cancel button for regular cabs. (turns airbag off when you have a baby seat up front).

 

Passenger airbag turnoff on my '04 Extra Cab as well

 

Passenger air bag on/off switch on the Extra Cab

 

This

 

On Standard and Extended cabs, you have the choice of turning off the passenger airbag in case you wanted to put a rear facing car seat in the front.

You don’t have this option in a double cab, the airbag is always on.