Mounting under the drivers seat 
I've got other stuff under my drivers seat so BT won't fit there, but I don't know what it is!

It looks OEM though. We (my mate did it with me watching) put my BT unit behind the head unit, works fine.
Incidentally, regarding the IOS4 issue, 'ang on as I think things may be happening at Apple.

Yesterday Apple didn't acknowledge this problem, said it was down to the car makers to keep up with the latest tech, and that I should get my BT upgraded, stupid cow.
Today, I was told that they are working on a fix!!
Hassle them at Apple Support, (a 0800 number) the more of us that do - the quicker things will happen.

TonyZ