Molded plastic part

A molded plastic part comprising a body constituting a design surface, and a reinforcing structure projectingly provided on a design back surface of the body, the body and the reinforcing structure being monolithically molded as one piece by injection molding at one time, in one injection mold, from the same molten plastic injected through the same gate, wherein

• the reinforcing structure is formed by a combination of (i) a plurality of transverse ribs which are arranged at appropriate intervals in a longitudinal direction of the body, and each transverse rib extends in the direction intersecting with the longitudinal direction of the body;
• and (ii) at least one longitudinal rib which extends in the longitudinal direction of the body at right angles to the transverse ribs and connects the transverse ribs to each other,
• the transverse ribs are connected to the design back surface;
• one of the transverse ribs is provided as a first transverse rib on which the gate is located;
• and
• the at least one longitudinal rib is disposed so as to be separated from the design back surface via clearances between the at least one longitudinal rib and the design back surface, so that all resulting joined and solidified locations of the molten plastic which flowed in the injection mold lie in the reinforcing structure.