E60 Parrot Bluetooth - getting all speakers to work

[Billy_Whizzzz]

Had a Parrot Bluetooth set up fitted to my 55 plate e61 and the installer couldn't get all the speakers inc woofer to work with the kit making playing music not worthwhile as it only plays through the front speakers which sound very tinny. Fine for phone calls but not music. Any ideas how to connect the others if Parrot systems only work with the front s 4 speakers...?