Hi, the sat nav in my 2015 CX-5 is broken. Will not turn on, no radio or any other functions. I have taken it to the main dealer and they say the CMU (or something) is dead (part number BAAR 669 C0) and it needs a new one at a cost of £1200. Has anyone else had this problem? I'm thinking about replacing the entire unit with an aftermarket android auto type thing that would cost around £300 if I replace it myself. What are people's thoughts?