Here are a few suggestions on repairing installing replacing and maintaining your homes exterior siding.
Exterior Mobile Home Siding Repair
Typically the wood type exterior sidings used on mobile homes and manufactured homes if not maintained will start to break down causing a serious problem. The siding used is usually "MDF" board. Ask your local paint guru about recommendations for stains or paint that will hold up for homes in your geographical location. If the siding is already starting to break down you have basically 3 choices.(1) you can remove and replace to the bad pieces. (2) you can sheet over the exterior with something similar to what is called T-111 siding. (3) cover the exterior with vinyl. This is my favorite, because you can easily upgrade insulation by different methods and make the appearance of your mobile home better. By just using "house wrap" under what ever exterior cover up you choose can make a big difference in heat and cooling loss. The upkeep of vinyl sidings is minimal and will last for many years. If the mobile home is new start now with coating, staining or painting. Once again consult your local painting professional for suggestions.
Vinyl Siding Over Metal
I don't see any problems with putting vinyl over the metal siding commonly used on single wide homes. You would need to prepare for the installation by removing any metal corner channel and installing the J channel where needed. Use sheet metal screws and affix the vinyl to the high spots on the ribs of the metal, other wise the installation would be about the same as installing over any flat surface. Be sure to kill any rust with a wire brush and spray paint. Repair any air leaks that you see to help with the homes heating and cooling efficiency.
You can get metal siding panels and all your exterior parts you need from these reliable suppliers.