Pre-installed car kit - any suggestions?

I'm just in the process of buying (collect it tomorrow) a 2006 Prius T-Spirit. Whoever bought it new seems to have not only gone for the most expensive model available, but then gone down the list and ticked the box next to every single optional extra (right down to the £150 mat in the boot).

One of the extras seems to have been some form of hands-free car kit, in addition to the Bluetooth system built into the Prius. As best I can tell, it's some kind of THB Bury system, as you can see in the attached photo.

has anyone come across this kind of installation before? Any tips on what kind of replacement cradle to buy, since unlike the previous owner, I don't use an obsolete Sony Ericsson phone? Do I want a universal THB Bury Bluetooth cradle, or is that going to conflict with the car's own Bluetooth? Help!

 

Aha!

Found it on techdoc.toyota-europe.com

It's a "Bluetooth Complimentary Kit"

Still trying to find a manual rather than just an install guide for mechanics...