Further to my post on 10/12/07. After a few days of fault finding, prodding and generally making a nusicence of myself asking mechanics daft questions i think my problem is almost certainly the back right height sensor. I have comprehensivly checked the bags and pipes for leaks and found no leaks whatsoever. Since i releveled the car yesterday morning it has remained at the same height. But start to clean or even touch the height sensor and it will drop within a few hours. So i'm gonna change it on Saturday.
One garage told me i needed to plug it in to testbook to recalibrate and 2 others said they never bothered and have had no problems. Anyone done this job before??. All i plan to do is support the body so that it won't drop when i unplug the old sensor, fit new one and start car and and pray!!!.
Dom