Silicone grease on weatherstrips will make them last longer, seal better, and not stick or squeak. Apply silicone grease with a clean cloth. During very cold, damp weather frequent application may be required. See "Recommended Fluids and Lubricants" in this handbook.
Your vehicle was designed and built to resist corrosion. All body sheet metal components are warranted against rust through corrosion. Application of additional rust-inhibiting materials is not required under the corrosion coverage and none is recommended.
Repairs to correct damage or malfunction caused by after manufacturer rustproofing are not covered under and Saturn warranty.