o.k, I have finally found the answer to my own question. Seeing as I was inundated with responses
, I went out and tried to track down this noise, especially difficult with just one person having to pull a door handle and peer into the bonnet. Anyway I have finally tracked the noise down to the lights
It seems I have the xenon lights that have the auto levelling device. When the door handle proximity sensor detects my hand it autmatically levels the lights!!! Why it does this I don't know as it carries out the levelling routine when the lights are switched on. Anyway hopefully not an expensive fix just a quick lube.