I now have the surround off, just like the photo.
I used a plastic spoon to prise it off in the end - seemed to work well and no scratches.
I have ordered a Parrot ikm9000 and the adapter cable required, will fit it in the week.
Looks like it should be a good setup - will leave the existing stereo and stalk controls intact and give me proper hands-free, and only 105 quid all in.
Thanks again, Joe.