Care of special surfaces?

[fongster]

What do you folks recommend for cleaning and preserving the following:

A) The finely textured, matte charcoal or black poly plastic found typically under doors and bumpers?

B) The matte or satin-finish black plastic or metal (I think it's sometimes painted, sometimes color molded in) surfaces usually found near or on sideview mirrors or the back edge of the Highlander's front doors?

Thanks.