If it's anything like my Audi A4, which is probably is as it's a VAG car, the drain holes under the battery will have clogged up.

The water builds up, filling the plenum chamber (where the battery is), and spilling over the bulkhead and going on to fill the footwells. If you're really unlucky (as I was) the unit which control the central locking etc is under the carpet just infront of the passenger seat and will become waterlogged and stop working.

So..

Take the battery out, if there is water you will need to find the rubber plugs and push them through. If there isn't water, do it anyway.

Next lift the carpet and prop it up, sit an electric heater (not too close though), have a window open a few inches as well, and wait a few days/a week.

If the central locking stops working, a new central convenience module costs £100+ and then £50+ for a VW/Audi specialist to recode it to match your key fobs, etc. When this happened to my Audi I rang the local Audi garage (Newcastle) and they refused any contribution towards repairs, even though a few years ago there was a recall to remove the rubber plugs that cause this. In the end they wanted over £700 to fix it, reduced to £150 to sort it out myself and using a local specialist to recode the CCM.


Fingers crossed!