Using these Rally Armor UR V.2 mud flaps is easy. Just take the set from the package, which includes four flaps, the necessary hardware, and instructions. Since they are a direct fit, you don't need to drill any holes in your vehicle. Simply attach them to the four corners of your 2008 - 2014 Subaru STI or 2011 - 2014 Subaru WRX hatchback using the included stainless - steel mounting brackets. As for maintenance, you can clean them with regular car - washing soap and water. When it comes to cold or hot weather, don't worry. The flaps are made from flexible yet durable urethane that can handle different temperatures. But remember, these V.2 flaps are not compatible with V.1 flaps or hardware, so don't try to mix them up.