A vehicle panel assembly and related method are provided. The vehicle assembly includes a push plug that is movable between a pre-installed position and an installed position where the push plug is aligned with a hole in a vehicle panel. A fastening post extends from the vehicle panel and is received in an aperture in the push plug. An engagement member projects from a side of the fastening post and retains the push plug on the fastening post when the push plug is in the pre-installed position. The aperture is larger than the fastening post in at least one dimension such that the engagement member of the fastening post does not retain the push plug when the push plug is in the installed position. This allows the push plug to fall from the vehicle panel if the push plug is improperly installed in the hole.