My signum had the same creak at the front as my Vectra did but i never fixed it on my vectra, tried tie rods & ends , droplinks etc etc but the one thing i didnt change was anti roll bar bushes.
Anyway ive changed them on the signum and the creak has now Gone.

Thought i`d post to let you all know that if you get a horrible dry creak noise from the front when you go over certain bumps this could be your problem.

Big thanks to Mark(gsi) as he pointed me in the right direction a while back.

One more job to do........ tensioner and belt change, parts come Tuesday .. Get ready for the P.M`S Duncan (lol).

Cheers guys