A method of pre-applying a bolster assembly to an interior trim part includes the steps of applying a base skin layer to a groove of a first nest, applying a bolster skin layer to a second nest, positioning the first nest in an open position, and inserting a leading edge of a bolster skin layer in the groove of the first nest when the first nest is in the open position until the bolster skin layer engages the base skin layer. The bolster assembly can be attached to the interior trim part by a Foam-In-Place (FIP) or Low-Pressure Molding (LPM) operation. The interior trim part may comprise a dashboard garnish, an instrument panel (IP), a door panel, and the like. A boss locating portion can be integrally formed within the base skin layer and is used for locating the bolster assembly on the interior trim piece during the manufacturing process. Because the bolster assembly is pre-applied to the interior trim part prior to the FIP or LPM operation, the bolster assembly can be positioned at the bottom-most portion of the groove to provide a consistent fit and finish, while reducing scrap material and cost of the interior trim part.