Many of the custom cars were actually only "semi-customs", with Dietrich assembling Packard-made bodies with special touches.

[1][2] Packard introduced the Twin Six to stay competitive with Marmon, Pierce-Arrow, Rolls-Royce, Renault and other luxury brands.

The standard paint scheme for open cars, touring sedans, phaetons, and runabouts was Packard blue with cream yellow striping on body and door panels, with black used on the underbody, radiator, fenders, chassis and running gear with no striping.

The cooling system was improved and a new Bendix-Stromberg EE-3 carburetor with an automatic choke was introduced, increasing power somewhat.

A single dry-plate clutch replaced the earlier twin-plate model, matched to a floor-shifted three-speed manual transmission and a new one-piece driveshaft.

The shorter wheelbase (Model 1005) was available with at least ten different styles of bodywork, ranging from the two-seat Coupe Roadster to the five-seat Formal Sedan.

[8] An "Aero Sport Coupe" bodied in-house and a LeBaron-bodied "Runabout Speedster" were available on this wheelbase; only around ten of these two types were made.

For the 12th Series of 1935, the engine gained aluminum heads and was stroked by a quarter inch, bringing up the displacement to 473.3 cu in (7,756 cc).

The only differences were a radiator angled by five more degrees, the oil temperature regulator was redesigned, and the shortest wheelbase model was discontinued.

The fenders were of a heavier design than on previous years' models, while a column shift became and option alongside the center mounted shifter.

5262 examples were built in total, with the top sedan as the All Weather Cabriolet by Brunn & Company for US$8,510 ($184,202 in 2023 dollars [5]).

In October 1935, American President Franklin D. Roosevelt gave Joseph Stalin an armoured Packard Twelve, which became the dictator's favourite automotive vehicle for many years.