Genuine Mercedes-Benz Parts and Accessories fit your vehicle like no others can. They’re engineered specifically to function with their fellow parts and systems, and they’re constructed from the finest materials available. They’re also subjected to rigorous testing, which means each part comes fully certified. In the end, you can be sure that your vehicle will perform up to its potential, mile after mile, with this Window Guide Rail for your 2008-2018 Mercedes-Benz vehicle. Mercedes-Benz Parts & Accessories Limited Warranty.