Every time I see a picture taken of someones dash, it shows the little symbol with their door open. I have tried every door on my car and no symbol! Is this something that needs to be turned on or something? 2000 A6 4.2L

 

On the bottom side of the windshield wiper stalk (right side of steering wheel), there is a small button. That button toggles on and off the driver information display in your dash. That's where the "open door" diagram (and a ton of other info) appears.

 

its weird, because all the gas mileage info and stuff shows up and i can cycle through everything. weird...

 

Leave your door open, and turn on your car. Shift into gear and you will see the diagram. It appears when the car is trying to warn you that one of the doors is open/ajar. Works for the trunk as well.