I take my car to vw world in kensington (sydney) to get serviced.

The recent rain drenched the footwells front and back passenger side and it seems that if part of that regular service is not cleaning the sunroof drain tubing, the one that empties in the front tire well, then you will get this problem.

I am a bit disappointed that a VW specialist mechanic who might be very adept and efficient at doing the typical engine service intervals does not appear to follow the check-list in the service manual.

Although the car did spend part of its first year of life parked outside among trees, the last two years were relatively vegetation free so I conclude that blowing out all the water drain paths once a year are absolutely necessary unless you wish to start growing mushrooms in the underlay