Hi there,

 

Upgraded from Stream to Stream MP3, works fine apart from if I play CDs from the changer it's very tinny, distant sounding. Guessing it's a wiring issue but no idea what to do, any ideas?

I'd make sure that the wiring inside the quadlock connector hasn't got a dodgy connection.

Had a look but everything's at the back. I did notice it stopped being able to see the changer CDs, came back when I took one out and put it back. Also, the rear wiper isn't working, could that be related?

*everything's fine at the back

The wiper requires the door to be closed. Maybe check that.