What should trigger the lights in the door edge (red on rear edge, white on underside)?

I would expect them to come on whenever the door is open, but nothing happens. Do they only work with certain Packages? I have all except Technology and Cold Weather on my '06 A3.

 

I didn't think this feature existed on the US models. I have tech and cold weather packages, and if there is a way to activate it I haven't found it yet.

 

im like 99% sure mines come on in certain situations. however i dont know exactly how it comes on either, ill check it out later.

 

A4 has lights. We have reflectors.

 

That doesn't explain the white lens on the bottom of the door, nor the specific picture of them in the '08 A3 sales brochure.