The airbag light is a post MOT failure. The engine management light was on for the MOT and the mechanic did check the fault codes but could find nothing wrong! And given the lovely design of the Megane the chances of me checking the bulb are zero as even the guy from the AA failed to change the headlight bulb for me.
I'll take it in somewhere (not Renault as in my experience they are robbing so and so's!! - wanted to charge me £60 to change a headlight bulb once). Just thought I'd test the water and see if anything obvious stood out as causing most of the probs in case they try and fleece me
It was the fact that the window seems to start working again when something else breaks and that the EMU is reporting phantom faults that lead me to hypothosise that it could be a "general" electrical failure somewhere. But I'm car clueless I'm afraid!
Thanks for the advice! Much appreciated.