hi all
Looking to install an aftermarket headunit (Sony MEX-BT4700U)

to my s4 but there seems to be quite a lot of different facia plates to choose from. i kn ow i need something for the bose system and something for the ariel bu can anyone guide me in the right direction. the car is a 1999 s reg a4 s4 b5 avant with the bose system.

many thanks