No idea where it is on these, but check the cabin filter. They are often under the passenger dash, or behind the glovebox.

I don't think anyone can give you an exact answer on an internet forum, but the way you're going to have to go is to remove the seats, centre console, carpets and underfelt. In any case these will not dry in situ. You'll need to hang them over the washing line to thoroughly dry.

Sit inside the car with a good torch and get someone to spray water with a garden hose all over the car. With a bare floor you should be able to see where the water is coming in. It's then a case of looking to locate the exact point of entry and sealing it. When the leak is cured and the carpets are dry you'll have to re-fit them.

Be mindful that under the front passenger seat is the Body Control Module. The well that it sits in often fills up with water on these, and if so you'll notice the windows and central locking doing their own thing. So make sure the BCM is kept dry.