tyger/fatboyjon
What year is the Focus? Some earlier models had the pollen filter under the front wiper trim/scuttle,If not resealed properly they would leak water into the footwell causing misting troubles.
Is the rear wiper wash working? The pipe runs down the ns front lower sill of the car and i have seen these burst or come adrift near the passenger footwell.
Has the car had any accident repairs done? Any badly fitting doors/seals/grommets will give water ingress/misting problems,as suggested above unusually wet carpets would be a possible result.
If the heater matrix has gone (higher mileage) you would notice a srong smell (coolant)A drop at the coolant level resevoir,and poor heating,Its common in engines with the wrong spec coolant corrosion Inhibitors added.