Using this D2 Racing RS coilover kit is easy. First, make sure your car is on a flat and stable surface. Then, install the coilover kit according to the instructions that come with it. Adjust the height and preload to your preference, but don't over - tighten. When driving, you'll notice better handling and a smoother ride. As for maintenance, check the mounts regularly for any signs of wear or damage. If you see any rust on the parts, clean it gently and apply a protective coating. And remember, if you ever need to, this kit can be rebuilt and serviced in the US, so don't hesitate to get it checked out if you have any concerns.