Sanding the bases won't really do anything because the height of the clip is determined by the mounting peg. Where the trim piece sits in relation to the roof can only be determined by the clip in relation to the lip on the trim. Thus, the trim can only be held closer to the roof by either a clip with lower retaining arms, or spacing the trim piece downward by adding some sort of spacer between the higher arms of the white clips and the trim lip.