What is this phone holder looking thing under the bonnet?
 

The part number appears to be 480907659 but i can't find any info on it:Confused:

I have a feeling that it's some kind of air quality sensor? I seem to remember puzzling over that box when I was having a nose at my TCU (transmission control unit).

It's strange, its just dangles in there not and there doesn't seem to be a dedicated place for it

The "8" should be a "B"

https://www.ebay.co.uk/itm/Audi-A8-D...-/132200997709

It is held in place by one of the ECU box lid screws - the one to the right in your second pic.

Thanks for this. It looks like its totally out of place and should be somewhere near the vents. Another bodge for me to fix yay!

Its in exactly the right place in the car. Etka is showing it with other HVAC sensors, not its actual position. Andrew had a thread on it a little while ago, maybe with pics of it attached to the ECU box lid.

It's in the right place indeed. I just opened mine up and cleaned it, without touching the sensor surfaces! :tuttut:

This was the thread: http://forum.a8parts.co.uk/showthread.php?t=15437

Mine was left like in the first pic, thanks for that link now i know howto fit it properly.

Its the air quality sensor I believe - Used to determine whether or not to auto recirc. It should be sat in the path of the inflowing air to the blower motor....