I gather that a common problem exists on the older version C5's involving involuntary electric window opening. I have a 2.0HDI estate which I am growing to love, except for this peculiar problem. The passenger door window will not stay completely shut - when it is wound up, it immediately winds back down to about half way. Also, recently both front windows occasionally open by themselves - not the most desirable of habits during winter weather!! Has anybody got fixes for any of these issues?