Vanker

During the cold period a few months ago I left my car at the airport carpark, when I returned a week later I noticed that the drivers side window & windscreen had several scratches on it. Now my 1st thought was some **** at the carpark had put something on the glass. I then notice on here that other people have scratch isues. Is there a warrenty issue with impreza glass. The car is an MY02 WRX.