[6] The C-300 was a racecar aimed at the NASCAR circuits that was sold for private ownership to qualify for homologation purposes, with Chrysler's most powerful engine, the OHV 331 cu in (5.4 L) FirePower "Hemi" V8, due to the hemispheric shape of the cylinder head, fitted with dual four barrel carburetors, two overhead valves per cylinder with solid valve lifters, a race-profiled camshaft installed inside the engine cylinder block, stiffer front and rear suspension, and a low restriction performance exhaust system.

Measured at 127.58 mph (205.32 km/h) in the Flying Mile, and doing well in NASCAR, the C-300 aroused interest that was not reflected in its modest sales figure of 1,725, and the listed retail price of US$4,100 ($46,633 in 2023 dollars [11]).

In February 1954 the Mercedes-Benz 300 SL was introduced and sold in North America and was labeled the fastest production car of its time.

The 1956 300B was fairly similar externally, distinguished by a new tailfin treatment, but with larger engines, and a choice of two versions of the 354 cu in (5.8 L) Hemi V8 producing either 340 or 355 hp (254 or 265 kW), with a 10:1 compression ratio used to achieve the higher horsepower rating.

Colors were updated to Regimental Red, Cloud White and Black[10] while the tan leather interior remained.

[5] The 1957 model year 300C was corporately shared with an all new appearance for Chrysler products called the "Forward Look" and featuring a "yawning" wide trapezoid-shaped front grille which was unique to the 300C, "Vista-Dome" windshield, dual headlights, and gradually rising tailfins starting from the doors similar to Chrysler-branded products.

The exterior color list was expanded to offer Jet Black, Parade Green metallic, Copper Brown metallic, Gauguin Red and Cloud White[10] while the interior was tan leather standard and optional interior choices were available from the New Yorker list of which the 300 was based.

The car introduced red, white, and blue '300C' circular medallions on the sides, hood, trunk, and interior and was the first model to use the color scheme, and despite the late-1950s design trends that added ever increasing amounts of chrome, styling flourishes, intricate grilles and interior appearance features the styling of the 300C and subsequent generations remained minimal.

Thirty-five cars were built with an extremely rare option called the Bendix "Electrojector" fuel injection,[17] with which the 392 cu in (6.4 L) V8 was rated at 390 bhp (291 kW).

The exterior color list was updated to offer Raven Black, Aztec Turquoise, Mesa Tan, Tahitian Coral, Matador Red and Ermine White[10] while the interior was tan leather standard and optional interior choices were available from the New Yorker list of which the 300 was based.

[19] Power output remained about the same at 380 hp (280 kW) while the engine weight dropped by 103 lb (47 kg) and production costs were reduced.

Power adjustable swivel seats were standard but were synchronized to the opening of the door while accommodating a traditional six-way power adjustable split front bench seat, with a new "Natural Tan" leather upholstery feature called "Living Leather" that used a basket-weave pattern to promote air circulation in warm weather, while optional interior choices were available from the New Yorker list of which the 300 was based.

Instead of the normal V8 central intake manifold with carburetor(s) on top, the cross-ram consisted of two pairs of 30 in (760 mm) long tuned pipes that criss-crossed so that each set fed the opposite side of the engine.

[22] A special 400 hp (300 kW) "short ram" version optimized for higher engine speeds was produced for competition.

Only 15 "short ram" cars were produced; these were also fitted with the exotic but often troublesome French manufactured Pont-a-Mousson 4-speed manual transmissions developed for the Chrysler-powered Facel Vega.

Approximately 4 of these "Special Gran Turismo" are known to exist,[24] including one convertible and one with air conditioning; it is believed that 15 were originally produced.

Swiveling front seats were fitted as standard equipment but were modified to mechanical operation only initiated by the driver and not synchronized to the door when opened.

The bodywork was also redone for 1960, using Chrysler's new lightweight unibody construction and given sharper-edged styling with outward-tilting fins that were visually separated from sides, while the front grille adopted the corporate look used by all Chrysler-branded products, ending a tradition where the 300 had unique styling not shared with other Chrysler branded vehicles.

Small parking lamps below the headlights were likewise slanted and V-shaped, and the front bumper was canted up at each end, scoop-like.

[22] The standard equipment rear bucket seats continued with a full-length console from the dashboard along the tunnel containing the driveshaft, and were also offered on the New Yorker Custom coupe.

[29] The "AstraDome" instrument cluster which was sometimes called the "gumball" or "jukebox" due to its appearance continued to be installed on all Chrysler products for 1961.

[22] Inside, the 300 Sport Series hardtop coupe was installed with standard bench seats front and rear, similar to the Newport, while the 300H had standard bucket seats front and rear with the full length center console, and were also offered on the New Yorker Custom coupe.

This was also the last year for the AstraDome Instrument cluster for all Chrysler branded vehicles and the dashboard color now matched the leather upholstery and carpet.

Under the hood of the 300H the cross ram engine became an option, and there was a return to the inline dual 4-barrel carburetor setup of the 300E as the base powerplant.

With a slight power boost and a 300 lb (140 kg) lighter body, due to the 300H being shared with the Chrysler Newport/Dodge Custom 880 122-inch wheelbase which reduced overall weight, the 300H was faster than the 300G, but the loss of exclusivity coupled with high prices made this the slowest-selling letter series year yet, with only 435 coupes and 135 convertibles sold.

The redesigned, otherwise low-key interior featured an oddly squared steering wheel, shared with all Chrysler products for that year.

A 413 cu in (6.8 L) Wedge with a single Carter AFB 3614S 4-barrel carburetor, a regular intake manifold, and 360 hp (270 kW) was the new standard engine, shared with the Imperial.

[37] With the introduction of the Chrysler B platform Dodge Coronet and the Plymouth Satellite, the performance coupe tradition was handed off from the 300 and the subsequent letter series model naming convention was discontinued.

The 300M also had paint stripes along the lower body line instead of the chrome molding found on the non-letter series 300s, "300M" medallions on the sides, script "Three Hundred" badges and unique tail lights and bezels.

At an auction at the Robson Estate in Gainesville, Georgia on November 13, 2010, the sole 1960 300F convertible equipped with the factory 400 hp (298 kW) engine and the Pont-a-Mousson 4-speed sold for $437,250.