Thanks, spot on. Seems like I have similar issues to you. I started in the nearside doot cubby hole where I has stashed a rag, soaking! Straight away I found the join at the top had come adrift, nice and easy. So I try the washer again and out of the corner of my eye see movement.... and foam is bubbling down from the A pillar behind the glove box! I'm assuming it is another joint which has come apart, but unfortunately not, a split pipe. It hadn't broken like in the picture, I did that pulling the ends apart.
Anyway, I haven't time to mend that today, I'm hoping my A4 will have similar pipe and I can rob that next week.
The car used to live surrounded by trees, and although the plenum chamber was dry, it was very grubby and I wanted to makes sure the drain holes under the battery weren't blocked.
So, the cover comes off, then the wipers which allow me to remove the scuttle panel. I took the pollen filter out, but couldn't get the surround out as the nuts were just slipping underneath - but I was able to clean around it ok. Battery out (yes I have the radio code....) and then the three nuts to remove the battery tray. The bungs were quite clear, but I took the right hand one out anyway.
Some APC and it looked a lot better.
Refit is the reverse of removal, and a wipe over. Another box ticked.