To whom it may concern: The aluminium tube you "found" in the trunk of your car is the tube that holds the cable for the sliding roof. The opening/closing can be adjusted. To adjust,flatten the locking plate holding the lock nut. Hold the shaft with a screwdriver and tighten the lock nut. Bend locking plate to secure the adjusting nut. Don't tighten the nut too much. Just enough to make the roof open and close. It's that simple.Good luck.
Bill Lewallen Lexington,Ky.