Despite the four major updates of the Minor in its 23-year production run, very few actively designed "safety features" were ever engineered into the Minor's design. Provisions were made for seat belt fittings in the early '60s, but the rigid structure of the car's monocoque body made it dangerously unabsorbent to impact. For a short time in 1968, the thickness of the steel used in the bonnet and doors was decreased from 1.2 mm to 1.0 mm to act as a form of crumple zone, but as the wings continued to be made of 1.4 mm mild steel, the modification was pointless and ineffectual and was reversed in 1969 as it increased passenger compartment crush in collisions.