Bodywork and Glass Leaking windscreen
Mine was suffering from this problem quite badly, both footwells would fill up following heavy rain. I tried a tube of windscreen leak stop but that made little difference. I decided the only solution was to give in and fit a new seal. They are still available from VAG under the part number 251845121 at £31. I thought I might aswell replace the screen at the same time due to a couple of chips, I managed to source one from an independent screen fitter for £70 inc VAT. My windscreen frame was in pretty good order with only minimal rust on the seam edges on the bottom corner, this was enough though to distort the seal and let the water in. I ground the rust back treated it then gave the windscreen frame a few coats of fresh paint. The new screen was easy to fit using the rope trick and a couple of helpers. My footwells are always bone dry now even after the heaviest downpours.
New seal is the only solution long-term and is better done sooner rather than later as the rust causing the problem will only get worse.