As above. I'm kicking myself for not spotting this earlier - there was an old-sock smell in the car for a few weeks. But I went to shake out the rubber mats today and found that the passenger side was soaking - front wet through, and a smaller patch in the rear.
My first assumption - cos I've had it before, years ago - was [1] blocked ACC drain. I always used to be able to monitor the condensate as I had a concrete drive, but the current one is gravel so I can't so easily note the little puddles on both sides. But some googling also throws up the possibility of [2] blocked drain hole in the plastic lower windscreen surround.
Any thoughts on how I might clarify this? It would be good on grounds of expense and hassle to DIY it if possible. I should also say that when I've started the car lately, rather than defaulting to ACC/Auto it's come on in Econ. Again stupidly I didn't think too much of it - but is the system trying to tell me something? Surely it wouldn't know if an ACC outlet was blocked?
