The second generation, model W451, was introduced in November 2006, featured slightly greater length (increased by 200mm to) and improved crash performance while retaining the exposed, rigid steel frame, marketed as the "Tridion" frame and interchangeable plastic body panels.
The second generation, model W451, was introduced in November 2006, featured slightly greater length and improved crash performance while maintaining similar styling to the original Fortwo. The Smart Fortwo's second generation length increased by 200mm to, retaining the exposed, rigid steel frame, marketed as the "Tridion" frame and interchangeable plastic body panels.