Good luck!
Once you find the leak, the only thing you then do is "dry" the carpets.. Last night the VW dealer called me and informed me that the car was nearly ready but they' also advised me that the carpets really need removing & drying.
Why?
Apparently below the carpet is a foam underlay+sound denting.. If the top of the carpet is wet then it means the bottom is also wet, and water is likely to have accumulated. If i leave it, when it finally drys it will smell... bad...
Now the dealer suggest they need to remove all the seats(!) to then remove the carpet, put the carpet in a boilerroom and then replace.. circa another 400 quid...
Obviously Im not paying this, I'll just add it to the windscreen companys bill... but at the same time I'm a reasonable man......
I think you could simply peel back the carpet on the drivers side, maybe take out that seat, and go from there..