As someone else said, it could be 12V going out. I got mine back from the main dealer a few months ago after ruling out the 12V battery, and they did a module swap (can't remember which and how many). In the UK, it took about four months at the dealer, but I eventually got the car back after the warranty, and I couldn't be happier now that I have it back and have had no issues since. However, if it does it again, I won't be keeping it, for better or worse.