when i bought my car last year,my96 wrx,i noticed the spare tyre hole was full of water and after posting on scoobynet,everyone came back saying rear lights....done them and it seemed fine but the weather has turned ****ty again and the problem has come back
if i get the heater on and totally demist all the windows(which takes ages)then get out of the car for 5 minutes,when i return it all misted up again really bad.....is this normal on imprezas.
if the problems is the rear lights again i might as well buy some sti units while there out

 

Mine's about the same now. I had a rear light leak that's now been (hopefully) fixed, but I think everything's just got damp and needs to dry off.

Or else there's still a leak somewhere

 

Most mkes of car suffer from condensation in this weather, youwant to try driving something bigger with even more glass.
As for the water leak, have a check around the boot seal, as if the catch is not adjusted correctly, may allow water in. Also whilst in this area, gently ease the rubber seal off the lip edge and check to make sure there is a line of sticky "mastic" sealant along the top edge, as it has been known for the water to creep "under & over" this edge, that why the sealant is there, so check that too, if not still there, apply some.