The cars as we know it today is the result of thousands of innovations over the years.

The Oldsmobile Hydra-Matic of 1939 for the 1940 model year was enormously important. While using a manual gearbox today isn’t too much work, that wasn’t the case in the 1930s when it was something of a skillful chore. The arrival of a four-speed gearbox was a major change. 200,000 Hydra-Matic equipped cars would be sold before world war curtailed civilian production, though the system would then make its way into the M5 Stuart and M24 Chaffee, both built on GM’s Cadillac production lines.

AUTOMATIC GEARBOX: Oldsmobile (1939)

In 1939, Buick fitted flashing red lights to the back of its cars to act as indicators; within a year, Cadillac, Hudson and LaSalle had followed suit. But years before this, drivers were expected to signal their intentions by sticking an arm out of the window and indicating if they were turning left or right, or slowing down. Then trafficators arrived: orange-illuminated arms that popped out from the side of the car and some automakers stuck with these until the early 1960s.

FLASHING INDICATORS: Buick (1939)

Plymouth was the only division of Chrysler to offer open-topped cars in 1939, and while rivals were also selling convertibles, none had one on its books with a power-operated roof. The car pictured is a 1939 Plymouth Deluxe convertible, which was powered by a 201ci (3292cc) six-cylinder engine.

POWER CONVERTIBLE ROOF: Plymouth (1939)

The Packard Super Eight One-Eighty became the first series-produced car equipped with power windows when it made its debut. Called Automatic Window Control, it was hydraulically operated. The model just beat Lincoln, whose 1941 Continental included vacuum-operated power windows. The Packard system used brake fluid to move the windows up and down. It was slow and prone to damaging leaks when not properly maintained. A very primitive air conditioning system that took up nearly the entire trunk also made its debut as an option on this truly groundbreaking car.

POWER WINDOWS: Packard Custom Super Eight One-Eighty (1940)

Chrysler may have been the smallest of the Big Three, but it was on an innovation roll after WWII with a series of groundbreaking and long-enduring inventions. It would be another decade before most car makers would discover disc brakes but as early as 1948 the Chrysler Crown Imperial featured them, on all four wheels. 

DISC BRAKES: Chrysler Crown Imperial (1948)

As already mentioned, the first power-assisted windows were fitted to a 1940 Packard, but a hydraulic set-up was used. It wouldn’t be until 1951 that electric-powered windows were fitted to a car; Chrysler’s Imperial was the first to feature them.

ELECTRIC WINDOWS: Chrysler Imperial (1951)

It’s another win for the Imperial. Until this range started to offer power assisted steering (PAS) on its 1951 models, PAS made a profound impact; Imperial’s system was called Hydraguide, and was actually based on expired patents by GM-contracted engineer Francis W. Davis (1887-1978) from the ‘20s

POWER STEERING: Chrysler Imperial (1951)

Cadillac introduced air suspension on its top-of-the-line models for the 1957 model year, giving a true magic carpet ride. GM threw everything at this flagship car; another first notched up by the car were memory power seats. It cost $13,074 – twice the price of a standard Eldorado, and the equivalent of $125,000 today – and was even pricier than equivalent Rolls-Royces. 704 were built in 1957-1958.

AIR SUSPENSION: Cadillac Eldorado Brougham (1957)