Using these StopTech rear sport brake pads is easy. Just replace your old rear brake pads with these new ones following your vehicle's standard brake pad replacement process. For normal use, these pads will perform great right out of the box. However, if you're planning to use them on the track, it's a good idea to do a few test stops to warm up the pads before pushing them hard. When it comes to maintenance, keep an eye on the wear level of the pads. You can check this by looking at the thickness of the brake pad material. If the pads start to get thin, it's time to replace them. Also, in cold weather, give your vehicle a short warm - up drive to let the pads reach an optimal operating temperature. Remember, if you have a 2003 WRX, make sure to measure your stock brake pads' dimensions before installing these new pads to ensure they fit your calipers. And if you have any doubts, don't hesitate to give us a call.