Anybody know where the motor for the powered-tailgate is located in a Veccy C 2006 CDTI StationWagen?

For a couple of weeks ago, the tailgate stopped during the close process, but seemed to get back to normal after a few runs. (first post from me about this matter here:
http://www.vectra-c.com/forum/showthread.php?t=85812 )

Now the powered-tailgate stops about mid-way almost every time and it takes several tries, including manual/force close to get it to operate normal.
What happens is that the tailgate starts to close normally, then stops somewhat in the middle as it has detected something obstructing it, and then keeps it there before slowly opening fully again. (The manual says that it will behave like this if the tailgate is obstructed during the close-process)

-It seems like it perhaps has some sensors or others that kicks in and prevents the motor to complete the closing of the tailgate.
Or perhaps the pulling-wire is dry, damaged, etc......
Any ideas??