Its for the headunit (radio/media)

Set it to 0, music/radio will stop when you turn off the engine.
Set it to 20, music will continue to play even when you turn off the engine. However it will stop when you exit the car (when you open the driver side door, technically)

 

From the entertainment system manual page 46

“Switch-off delay": enables the system to continue functioning for a certain period after the car has been turned off;

The system in this case is the entertainment system, so do you want to be able to play music with the car off for up to 20 minutes?

 

Thank you guys!

 

For those of you that don't pump your own gas, you can turn off the engine (as you should when refueling) and listen to the radio while the gas is flowing....

 

Get real Dino, my wife gets grumpy enough when I make her pump my gas, if I was sitting back listening to tunes, that would really p**s her off!

 

Oh man I always found this annoying. I guess I skipped this section in the manual! thank you

 

Also controls how long the lights stay on after you exit the car.