Many of the brand name trailers will sell replacement pads.
You can get the same type (maybe not the exact same size or color, but good enough) here: Trailer Pads
they are attached with pop rivets, usually aluminum.
If you mean rubber mats for a kick wall area, you can get those at a farm supply store such as TSC, just go for the thinner style than what is used for floor mats. They are attached by pre drilling a hole in the mat, and using either a wood or metal screw with a grommet that keeps it flush and prevents it from pulling through. Whether you use a wood or metal screw is determined by your trailer wall. Posted via Mobile Device