I bet you any money that its all built in and you have to get the whole armrest!
youre probably best looking for the part number on german ebay etc

Having raided the a8parts archives, I have found this which might help. You can see its a whole different insert, and in these models the first aid kit is relocated to the boot. I had the same ideas as you about a transplant, but its firmly in there. Maybe Elsawin will reveal how it comes apart. I considered also transplanting the whole armrest unit, however the LWB rear backrest is wider and sits at a more reclined angle than the normal seats, so the armrest would maybe not fit.....

http://forum.a8parts.co.uk/attachmen...1&d=1330030152

Thank you for this Ian. Excellent picture. Will do more digging.

I'm a bit confused as to why LWB backrest is wider...

Sorry, I'm misleading - I mean its deeper, taking advantage of the extra length in the wheelbase.

The width is the same, and I've has LWB seats in a normal SWB D2....

Thank you Ian

Based on that photograph I'm inclined to believe that a retrofit is possible, albeit a bit more difficult than simply undoing a couple screws. I'm down to give it a go though, I'm not sure I'm in need of a first aid kit, that's what emergency services is for. Any idea if this was also a US spec option?

http://www.ebay.de/itm/Audi-A8-6-0-W...#ht_2087wt_932

W12 LWB D2 for sale LHD with the rear toys

Here is standard arm rest. Seems to me geometry is similar.

http://forum.a8parts.co.uk/attachmen...1&d=1330101761

I looked at ETKA again and my understanding is that *backrests* for LWB and SWB cars with non-adjustable rear seats have the same geometry, since picture 885-60 applies for both LWB and SWB cars.

Backrests for electrically adjustable seats have different design and different armrests. Picture 885-80. LWB and SWB cars with electrically adjustable seats share the same geometry of *backrests*.

I made these conclusions based on how ETKA data is organised on pictures 885-60 and 885-80.

Link :)