mm the foam layer opposite the planar side of the planar heating element that is was seated on the protrusions 53 has a height of about 10 mm in some embodiments as shown in fig3 the protrusions 53 are arranged for example in a regular hexagonal grid or a regular arrangement in rows and columns in some embodiments the protrusions 53 may be arranged in a different manner such as in a triangular grid or a quadratic grid as needed when molding the foam body 10 and during the subsequent installation of the interior trim part 1 fig4 shows a planar heating element 10 by way of example as a heating mat in addition to heating strands 41 which are knitted into a non woven carrier fabric the heating mat has through passages 42 these are evenly distributed over the entire heating mat and formed by stamping for example the task of the through passages 42 is to ensure the through flow of foam material 31 when the foam material 31 is added into the mold cavity 54 this ensures an even and fast distribution of the foam material 31 in some embodiments a minimum diameter of the through passages 42 is about 4 mm in some embodiments to ensure a.