In 1976, the final prototype appeared, with the engine changed to a , the most powerful engine in VAZ range during Soviet era, taken from their newest model the VAZ-2106 (from which the production model of the first Niva generation was generally derived). It also featured permanent four-wheel drive and a transfer case with a lockable central differential. The VAZ prototype displayed better design and real-world performance than its AZLK counterpart, the Moskvitch 416, so was, after the 25th Congress of CPSU, approved for production in March of the same year. (The Moskvitch prototype was then rejected for serial production by the government.) It was the Niva 1600 (Field) for export, or VAZ-2121 (alternatively Niva 2121 or simply VAZ Niva) for the domestic market in the former Soviet Union. For domestic customers, it was described as: "A high-speed car with the improved capabilities and comfort of all VAZ models", and also as: "A combination of the speed and comfort of a Zhiguli with the capabilities of a UAZ". Actual production began in the following year on 5 April 1977, while the first export models appeared in 1978 at the Paris Motor Salon and rapidly captured at least 40% of Europe's market for four-wheel drive vehicles, making it Lada's top-selling export. Moreover, it became the only Soviet car that was ever sold in Japan, starting from early 1980s, inspiring their Suzuki Samurai. Because of export demand and the higher priority given to exports, domestic customers faced long waiting lists, despite the fact that the car was developed primarily for the Soviet people, as mentioned above.