Audi A3 - Water ingress - cap boiler
Problem with soaked carpet in drivers footwell, no sunroof, no obvious point of entry.
Will start poking about in accessible areas under bonnet and see if there are drains blocked.
No electrical problems yet and may have to consider taking seat and carpet, soundproofing out to dry.
Anything obvious I am missing to gain quick fix?
Audi A3 - Water ingress - cws

Check the plastic trim at the bottom of the windscreen is seated correctly ie there's no gaps between the trim and the glass - water can run down and then find it's way in via the pollen filter housing. Get it sorted sooner rather than later as it can cause all sorts of electrical problems, resulting from corroded joints etc.

Audi A3 - Water ingress - cap boiler
Thanks, have encountered dampness and cleared drains, amazingly the dry spell conspires to assist, but have confidence. Local Audi dealer brilliant and assisting now and am confident all trim will be stripped out and dried. Whew.
Audi A3 - Water ingress - cap boiler
Sorted, stripped out and all dried. Problem stemmed from failure in sealant around door speaker.
Revealed, tested and seems to be fixed.