Hi - We’ve got water that is soaking the rear carpet. There’s also a sloshing noise you can notice sometimes when driving along. Any thoughts on this? it’s the TT Quattro convertible 2016 model.  reading up a bit it could be the drainage system?  otherwise not sure and there’s a lot of water.  Any suggestions to try or get it over to local mechanic. We’ve got an Audi dealership but stopped taking as super expensive for no apparent reason!