Properly cleaning & polishing your vehicles metal parts can really help to enhance the overall look of it and is a great way to finish it off after paying attention to the other areas. Parts of your vehicle that could be polished might include the wheels (or certain areas of them), exhaust tips, trim details & badges, chrome bumpers, grills and under bonnet components like the valve cover, reservoir filler caps, piping and manifolds.
Prior to polishing, metal parts should be thoroughly cleaned like the rest of the vehicle. A diluted all purpose cleaner and a stiff bristled brush can be used for dirtier areas, otherwise a normal car shampoo product should be sufficient.
Metal parts also can be clayed if necessary after cleaning to remove any bonded surface contaminants such as road tar and tree sap. For non-chrome parts a fine wire wool can be used in conjunction with a designated metal polish product to remove any oxidation or staining on the surface. Wire wool should not be used on already highly polished areas as it may introduce fine scratches or hazing and dull the finish.
Any parts that have been rubbed down with wire wool should be wiped off with an older, used micro fibre towel to remove any metal fibres and product residue and should then be re-polished, this time working the product in with a suitable sponge or micro fibre applicator pad and buffing off to a shine with a fresh micro fibre towel. Chrome or highly polished parts should be polished with a non abrasive designated chrome or fine metal polishing product which should be worked in with a sponge or micro fibre applicator pad and buffed of with a clean soft micro fibre towel.
The polishing & buffing process can be repeated a number of times in order to refine the finish further. Once cleaned and thoroughly polished metal parts should be sealed with an appropriate product in the same way you would wax the paintwork of a vehicle. This may help to add a little more in terms of shine to the finish but the main reason for doing this is to protect it.
Once sealed the metal will repel dirt, contaminants will not be able to bond to the surface and water will bead up and run off the surface helping to prevent staining. Sealing after polishing also means that metal parts can easily be brought back to a high standard of shine and finish with just a light clean if regularly maintained.