Bit of an update if this helps others, I took the glovebox out yesterday trying to track down this fecking rattle thats driving me insane. I discovered that the back of the glovebox has bowed in slightly meaning it wasn't making contact with the switch, my ghetto fix was to superglue a thick bit of card to the back of the glovebox door so that it now makes contact with the switch plunger. Works a treat now
I know the ccm will shut the light off after a few hours but this must have been draining the battery to some extent every time the car was switched off - I'd recommend others to check as there was nothing especially amiss - I think its an inherent design issue.
Also cured the noise from the recirc fan, there was a strip of tape which had been wrapped around the wiring loom that had been sucked into the recirc flap and was creating a turbulence noise like when something is partially blocking a hoover
But couldn't find anything else loose thats causing this rattle - it sound like something clanking about in a fairly big hollow space
Going to have another go today and take out the ccm to see if there is anything further back.