Hi
It sounds to me, that the hollow tube you speak of, related to the cable that is attached to the sunroof. When the sunroof is opened, the cable fills the tube, instead of dangling in the trunk.

-Larry

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D