OK so there's confusion.
I have a Bose (as in the Bose DSP in the boot). Which makes installing things like Parrots and Aux in really rather tricky unless you cut it out of system entirely. Per my most recent post I have the MM head unit.
TT for some reason thinks (thought?) I had a Bose head unit. And there is no USB behind the blanking flap on my GT
So everyone's on the right page
My name's Catman
I have a GT
My GT has a Magneti Marelli Head unit with no USB or Aux socketry behind any flap (although it's possible that the socket 'C' on the back may well allow such functionality)
I also have a Bose DSP in the boot. This means that if you splice a Parrot or something similar in by using the speaker plugs as you would do with most installs (cf 4200) we have no real idea what's going to happen with the DSP amp. It *might* be just fine or it might go a little bonkers.
Hmm, if I got a cheap one, I'd be tempted to give it a whirl. Given these are speaker level outputs, and assuming the centrepoint magic is not that intrusive it might still work....
C