Ive searched and searched but can’t seem to get a clear answer...I have a 2012 G550 and I’d like to replace the COMAND head unit with an Alpine Halo unit. My G has the fiber optic HK system but I can’t find if there is an adapter available so I don’t have to replace the factory amp. Any know for sure or can point me in the right direction? I went to an car audio place today and they quoted me $2700. TIA