Hi I thought I would share my challenge with trying to stop the passenger foot well turning into a pond, I had removed the air vent from the wing and tested for water coming out, which it was fine but yet the floor was still getting wet, what I discovered was that the rubber grommet had acuatually gone brittle and split hence letting water seep into the car still,
I ordered a gromet elbow which comes with a new pipe to,
I removed the interior a post trim ( best disconnect battery) by roving the airbag badge there's a torks bolt behind it, I then pulled the tube up through the dash and swopped the rubber elbow, tip put a bit of grease around the flange bit, then feed it back down the hole it came out of, the next bit requires 2 people, using a thin pair of pliers try and fish the gromet out and pull it through so that it seals, it's a fiddly job but seems to have cured it!!!

Good work!

I had a similar problem but found that the pipes were just blocked with muck. A quick blast with an airline in the open sunroof blasted a load of muck out into the inner wing and all has been well (dry) ever since.