99 e320 water under rear seat behind driver ????
Headlight, fog lights and tail lights with problem can be the headlight switch, better verify it with a multimeter.
Sunroof, maybe it is stuck, you will need a lot of patience and an oil like WD40 to release it, I hope the cable or the engine that moves it is not broken.
For the air conditioner, here we have many topics related to this, maybe one of then can help you.
Best regards,
Sergio


