The Kenwood amp in my 2021 Plus four is behind the back panel on the passenger side - I fitted a pioneer radio beside it as I couldnt get reasonable bluetooth radio here in Ireland - I removed the musicstream inputs to the amp and connected the radio - Lo and behold the bluetooth app for the radio on the phone controls the radio and with it the speaker levels!! so I have proper output from the front speakers as well as the back ones, and get all my music from the phone through the radio control app( a Pioneer!) as well as perfect radio. The aerial is passed through to the spare wheel area and a short rubber aerial mounted on the sloping back deck behind the hood!
Its really the best of all worlds!
Cheers!
