Hi, My 2007 XKR has a very annoying buzzing noise coming from the dash to the left of the steering wheel (rhd).  It looks like a microphone grill or similar.  Any idea what it is and why it buzzes?

In behind that grill is the air sensor and fan. Generally, the reason for the buzzing is a build up of dust. 

Try a squirt of compressed air from one of those computer cleaning cans.

Here is a picture, not my car, of the offending article.

I had tried blowing some air, used a vacuum, pushed a paint brush through, and then gave up. Simply never occurred to me just how much crap you could get there. Thanks for the pic, now I realise how disgusting my car must be.

You would need to remove the trim panel to get in there properly, as per the picture.

If that doesn’t solve the noise then you can get replacements for them.