I've got a 2003 B6 A4 which has served me almost perfectly for 6 years. On Thursday i took it out when it was raining pretty hard and about 500m from the car park, the alternator warning symbol started erratically flashing. I've since checked and the battery is fully charged and the alternator is charging the battery correctly. Soon after this it was followed by the traction control light, ABS warning light and most other dash warning lights. They were flashing but not 'fault code flashing' on and off, just randomly. Then the brake fluid check procedure came on the DIS, as if i'd just turned on the ignition. Then the wipers stopped, although they came back on soon after.
Today, the headlights also stopped working and i only have sidelights. The hazard warning switch in the car, the red light is flashes on and off. The fan on the air con randomly stops although looking at the unit, its still on and appears to be working normally. Finally (!) I'm pretty sure i can notice the car is not running 100%, driving along at a constant throttle it appears to hesitate, then its fine.

Reading other forums, I've seen some similar problems, all getting traced back to water in the ECU. I've had a look at mine and there's no obvious water getting anywhere. I've shoved some packs of silica gel around the ECU with a hope of drawing out any mosture i can't see. About a year ago i did replace the seized wiper arms which required removing the ecu so i'm still mindful this could well be the issue.
My question is basically, has anyone had this number of issues? Was it water or just a faulty ECU? Can anyone help me at all?