My radio ceased working ten days ago. Not used car since during very cold spell (-6/8C). Today battery so flat wouldn't even disarm. Phoned Renault garage to be told that my model (Megane Cabriolet 56 plate) was on recall due to this fault and that you need to disconnect the disfunctional radio during very cold spells or it drains the battery. Renault Dealer replacing the radio FOC.
Rhodie
December 2010