A3audiowner

Hi everyone , I've just spent £900 on a 2002 Audi A3 se.. It all worked fine the night I took it home.. The next day I set off to work . I put my bag in the boot and opened it with the key...it was very stiff as if not used in a while... Anyway as I reversed off the driveway I noticed the roof/reading light flickering. Thinking nothing of it I flicked it from the mode that comes on when doors are opened to the off position. Next I noticed my door locks on all four doors were popping up and down.. I dropped my daughter last school and drove off.. The locks dancing away.. i turned off the stereo to listen. I can hear a click behind the steering wheel, like a relay activating every second or two.. As it activates the lights flicker in time with it.. Also the square button on the drivers door pillar ( turns off alarm internal sensor) lights up and flickers in time....my central locking is unpredictable now .. Maybe it locks may be it doesn't.. Last time I tried it didn't lock and the indicators didn't flash, also I couldn't hear the pump but I did hear a double click inside the passenger door.. I have a few ideas but need help I think it could be the following caused.
1. Sticking boot lock or micro switch.
2. Sticking micro switch on any of the doors.
3. Faulty relay.
4. Faulty/sticky over-ride lock/unlock button on the drivers door.

Has anyone got any advice where to start.. I was thinking of disconnecting to boot from the central locking and just using the key see if that fixes it...

Hope some one has the answer thanks everyone