Hi all, I’m new here! So, I have a 2007 Audi A4 B7 2.0Tdi Avante. I have recently decided to upgrade my head unit to something more modern so bought an Xtrons head unit. Plug & play... I wired it in, it all works as it should, apart from a very annoying humming noise which gets worse when the headlights are on. Coming here is my last resort before I lose my mind so please help! Lol I’ve checked every ground on the car pretty much they’re all good and solid! I’ve tried an in-line filter, didn’t work. I’ve tried a single ground loop isolated between the RCA’s, didn’t work. I know that it’s not the speakers. Its a problem between the radios amplifier and the Bose amplifier but I have no idea how to solve this without rewiring all the speakers. Any suggestions would be very appreciated!?