Do all headlamp units have sidelights?

[staffop]

Not sure if this is a region specific thing but I've noticed from various pictures of X5 headlamp units that not all have sidelights. This is on both Halogen, Xenon, euro, non euro versions.
Unless I'm mistaken there doesn't appear to be any pattern to this. The pic below shows a Xenon unit without the 'hole' for the sidelight.

Just for clarification, the side lights are those which are activated at dusk before it gets fully dark. They use 501 capsule bulbs which fit through a small hole in the back of the highbeam housing.

Can anyone shed any light on this?