There were six-cylinder E21s, but all of the American-market ones had members of the M10 straight-four engine family, same as the BMW 2002. In 1977, this 2.0-liter engine was rated at 110 horsepower, which was a decent power figure in a year in which the most powerful new Camaro you could buy offered a mere 170 hp.
Volvo had made four-wheel-disc brakes standard equipment back in the 1960s, but BMW was still using rear drums on the early 320i.
171,768 miles on the clock, which is very good for a car from the middle 1970s.
In America, BMW made the transition from being a semi-marginal brand for weirdo car enthusiasts to being a mainstream status-symbol brand during the reign of the E21, so this car is the one that made BMW a star on this side of the Atlantic.