I apologize if I've missed this somewhere, but I sold my 2008 Clubman S a few years ago to a family member. They're running into an issue with the audio system not delivering sound when the car gets hot. The display is working but no sound. It's intermittent, but seems to be reliant on temperature. I'm not sure what the option was called, but it was the top tier audio/nav system available at the time. Any ideas?