Austin plant at Longbridge – in addition to a healthy demand for both products – production of the two cars continued in parallel for nearly 10 years. Indeed, production of ADO16 outlasted that of the Minor by only three years or so, before being replaced by the innovative, export-oriented, yet flawed Austin Allegro in 1974. Safety 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. The 1950 change from the "lowlight" model was made to comply with Canadian lighting standards, with higher and brighter headlights to increase visibility in fog and during dark Canadian winters. Australian models, and tourer models made in Britain and exported to Australia, featured safety glass windscreens and safety glass windows, to comply with local regulations. Australian models also had blinking indicator lights in addition to the standard trafficator arms on the indigenous Minor 1000. Morris quarter ton van and pick-up Closed van and open flat-bed ("pick-up") versions of the Minor were built from 1953 until the end of production. They were designed for commercial use with small businesses, although many were also used by larger corporations. Van versions were popular with the General Post Office, the early versions of these (to around 1956) having rubber front wings to cope with the sometimes unforgiving busy situations in which they were expected to work. Both the van and the pickup differed from the monocoque construction of the Saloon and Traveller variants by having a separate chassis. They also differed in details such as telescopic rear dampers, stiffer rear leaf springs and lower-ratio differentials to cope with heavier loads. The commercial versions were initially marketed as the Morris Quarter Ton Van and Pick-up, with a Series III designation applied from 1956. The names Morris 6cwt Van and Pickup was used