Quick Weathering for Bogies

There are a lot of very high quality r-t-r rolling stock models available on the market, pretty much all of them with bodies beautifully and realistically painted in appropriate colours. Unfortunately, the bogies are often not painted (self-coloured plastic) and the wheels have shiny faces.

This is not a criticism of the producers; I’m well-aware of the economics, etc. of producing r-t-r