At the beginning of the 2000s, Thomas began to introduce its most extensive updates to its product lines since the 1970s. For 2001, the Saf-T-Liner HD was introduced (combining the Saf-T-Liner ER, WestCoastER, and the MVP ER). Distinguished by its large mirror housings (integrating sideview, convex, and crossview mirrors into a single assembly), the HD also visibly shared several components from Freightliner, including its instrument cluster and headlamps. For 2003, Freightliner became the sole chassis supplier for the Saf-T-Liner Conventional, with all Conventionals becoming Saf-T-Liner FS-65s. In 2004, Thomas renamed the HD the Saf-T-Liner HDX.