change your wiperblades only if the blades are torn or broken, the most common complaint is that they are streaking.That is because the blades collect and smear the road grime on your windsheild, cheap and eay fix is to keep to winsheild clean windex the glass and also spray some glass cleaner on a rag and clean the rubber on your blades. you'll be amazed on the crap that comes off and your wipers will work like new again.being a retired mechanic from GM ive leared a few tricks along they way.