Set 853 was released under the "Technical Set" series in 1977 in Europe. It made it to the US in 1978 with the number 956 as an "Expert Builder"set. This "Super Car" features a 4 cylinder in-line engine, a 2 speed transmission, steering, and adjustable seats. The back seat arm rest even stows! Traditional studded construction is used almost exclusively.
For the time, this car had everything. It was by far the most complicated set of the first year, and would remain so until 1980. It is the only set with an engine, and has a long list of functionality. This first Auto Chassis set the stage for a series of increasingly complicated "Super Cars", culminating in the 8880. It is also huge and remains longer than any of the other LEGO® cars.