[3] The Duster coupe provided the compact-sized Plymouth Valiant with a sporty body style to attract customers.

The Duster was built on the Valiant platform and shared the same front end sheet metal, but featured a different design from the cowl back.

The Duster was also marketed as an alternative to the original Volkswagen Beetle, as well as the new class of domestic subcompact cars such as the Chevrolet Vega.

These marketing variations of the basic Duster design targeted customers seeking economy, cargo capacity, and/or performance.

The Plymouth Duster introduced in late-1969 for the 1970 model year was all Valiant from the cowl forward, but the rest of the car's sheet metal, save door skins, was completely different.

New surface-mount sidemarker lights replaced the previous flush-mount items, the taillamps became larger, one-piece units.

Following the design changes on the Valiant models, the Duster also received a new hood, grille, front fenders, bumpers, and taillights for 1973.

The rear window defroster/defogger was upgraded to an electric-grid style for 1973, which replaced the previous recessed package shelf air blower.

For 1974, Plymouth replaced the 340 with a 360 cu in (5.9 L) version of the corporate LA-series V8, de-tuned to meet new emissions regulations.

In the midst of the first oil crisis, 1974 would be the Duster's best sales year, with a total of 281,378 Duster-bodied cars produced, the majority of which being the six-cylinder and 318 V8 models.

Standard equipment included the 360 engine, dual exhaust, power disc brakes, full side tape stripe, rear tape stripe, heavier suspension, shocks, added sway bar, and 8 1/4" rear end.

[10] The 1975 models were mostly unchanged from the previous two years, with some exceptions: a new grille with a return of the Plymouth 3-pointed-'spear' affixed to the grille's center; catalytic converters were added to 225 Slant Six and 318 V8 models (the 360 was not equipped with a converter and its power was now 235 bhp (175 kW), due to the addition of a secondary air injection system, commonly referred to as a "smog pump".

The interior rearview mirror was mounted directly to the windshield rather than to the previous double-pivot roof bracket, and the parking brake was now foot- rather than hand-operated.

The 1976 360-powered Duster (and Dart Sport 360) was still without a catalytic converter, and while its power was down to 225 bhp (168 kW), the car could still manage 0–60 mph in 7.9 seconds when equipped with the 3.21 rear axle gearing.

[12] From 1974 to 1975, actress Judy Strangis was a TV pitchwoman for the Plymouth Duster in the role of "Mean Mary Jean," wearing a football jersey and short denim hot-pants.