Not possibly the heater radiator leaking?
Hi mate , its a really common problem on these having blocked drains and wet footwells by the sear only not near the front really ,
I'm fairly sure its the blocked drain as I first thought matrix but its not losing any coolant at all an we removed about 7l of clear water from the carpet and I licked it to confirm its not coolant ,
Just wondering of anyone's had to deal with this at vw poss a tech with the procedure or cleaning out , I've heard they hold 15L of water each side I the chassis and then back up in yo the footwell ,