A housing assembly for a printed circuit board is mounted on a vehicle body by pressing a collar nut or the head of a collar screw past a plurality of fingers of a housing assembly so that the fingers retain the nut or screw head in place. The module is then pressed against the vehicle body so that the collar nut or collar screw is lifted while the retainers are deflected outwardly and a tool is used to tighten the screw into a nut or the nut onto the shank of a screw to clamp the printed circuit board on the housing against the vehicle body.