The Curt Manufacturing Class I Trailer Hitch Receiver with Drawbar, item # 11114, for your 2008 Saturn Sky, will not void the vehicle warranty as long as all of the towing limitations of the vehicle and the hitch are closely adhered to.
There is a federal law called the Magnusson-Moss Warranty Act, which states that unless the modification to your vehicle, in this case the hitch, caused the problem your warranty must be honored. This being said you will need to use common sense precautions... view full answer...