I looked at some detail at this type of camera, and took the light out on my X3. All that comes out is the white cover - there appears to be some kind of PCB that runs across the length of the handle strip where both plate bulbs are and presumably the hatch switch too. I think it would require a modification to that strip to remove the section with the bulb holder to give enough space to mount the camera module up into the recess.

Have a look - just pop out one of the plate lamp covers and you'll see what I mean.

The whole part is 51133403611 - and the removal is quite straightforward but requires some care as the 'finisher' that it fits into is held onto the trunk lid with 6 panel clips that require being popped out after the removal of the 2 torx screws.

I may see if I can get hold of a handle strip from a scrapper and perhaps look at modifying it.... probably worth a go as I like the look of these plate lamp cameras....