After I replaced my headliner I don't remember how to reassemble the dome light.
There is a black plastic piece that apparently goes behind the headliner but I don't see why.
The light fits perfectly onto the studs hanging down from the ceiling without it.
I think if I try to put this plate in between it is going to push the headliner down too much.
I have looked for a picture of how it's supposed to be online but can't find anything.

 

You're probably not going to get much help without pics.

 

Here's the part I'm talking about

 

Does this diagram help?

http://www.realoem.com/bmw/enUS/show...34#63316962023