Using this D2 Racing RS Coilover Kit is easy. First, you can adjust the height and preload according to your needs to get the best performance for your 2005 - 2009 Subaru Legacy. The 36 - way dampener and rebound adjustment allows you to fine - tune the driving experience. When installing, make sure to check the compatibility, especially for the pillowball upper mounts or top mounts as they may vary in different applications. For maintenance, regularly inspect the Teflon - coated threads to ensure there's no rust. Since it's rebuildable and serviceable in the US, if you encounter any issues, you can get it fixed professionally.