A method of making an iridescent, vehicular trim assembly is provided that includes: molding a polymeric base comprising an exterior surface; and over-molding an element over at least a portion of the exterior surface. The element comprises a polymeric, translucent material and an exterior surface with an integral diffraction grating having a thickness from 250 to 1000 nm and a period from 50 nanometers to 5 microns. Further, the molding can be conducted such that the polymeric base is molded with a tint. The method can also include forming a plated region over the exterior surface of the base. In addition, the method can also include cleaning the plated region with a plasma-etching process before the over-molding.

A method for the manufacture of an interior cladding part with a visible side and a flat heating element includes arranging of the flat heating element as foam mat in a foaming tool such that the flat heating element abuts with a first flat side, which is facing the visible side of the interior cladding part to be manufactured, against an interior surface of the foaming tool, and introducing a first foam material into the foaming tool on a second flat side, opposite the first flat side, of the flat heating element such that the flat heating element is only back-foamed on the second flat side. The first foam material connects with the carrier element and the flat heating element.

A method for forming an in-mold coating multi-layer coating film includes: forming an uncured first in-mold coating film by injecting a specific first in-mold coating material composition (X) between a molded base material and an inner wall of a first film coating mold; heating and curing the uncured first in-mold coating film; separating the first film coating mold from a surface of the cured first in-mold coating film; providing a gap between the surface of the cured first in-mold coating film and a second film coating mold; forming an uncured second in-mold coating film by injecting a specific second in-mold coating material composition (Y) between the surface of the cured first in-mold coating film and an inner wall of the second film coating mold; and heating and curing the uncured second in-mold coating film.

A method for forming an in-mold coating multi-layer coating film includes: forming an uncured first in-mold coating film by injecting a specific first in-mold coating material composition (X) between a molded base material and an inner wall of a first film coating mold; heating and curing the uncured first in-mold coating film; separating the first film coating mold from a surface of the cured first in-mold coating film; providing a gap between the surface of the cured first in-mold coating film and a second film coating mold; forming an uncured second in-mold coating film by injecting a specific second in-mold coating material composition (Y) between the surface of the cured first in-mold coating film and an inner wall of the second film coating mold; and heating and curing the uncured second in-mold coating film.