In 1955, the first "comfortable mass-produced" monocoque all-wheel drive vehicle appeared, the M72, with a four-wheel drive system adapted from the contemporary Soviet GAZ-69. It was the brainchild of Vitaly Gracheva, assistant to the GAZ-69's chief engineer, Grigory Moiseevich. It used a standard Pobeda transmission, mated to the GAZ-69 front axle, leaf spring suspension, and transfer case, with a brand-new rear axle (used on no other vehicle, a rarity for Soviet car production). The body had fourteen panels added to strengthen the floor, frame, doors, and roof. Trim and interior were otherwise the same as the M20, and in all, 4,677 were built by end of production in 1958.