For 1980, the X bodies were resized to match the previous downsizing of GM full-size and mid-size cars, along with transitioning to front-wheel drive.

As the 1970s progressed, the popularity of import-brand vehicles (such as the Honda Accord and the Volkswagen Rabbit) led to declining market share held by American manufacturers in the compact segment.

Though downsizing of the full-size B and C-body platforms and the A-body mid-size lines was crucial to the future of the company, the two redesigns placed GM model hierarchy out of alignment; though officially a compact, the X-body Nova became dimensionally larger than the Malibu (a year after becoming closer in size to the Caprice than the Chevette).

To realign the X-body platform in size between the A-body and the H-body subcompacts, GM commenced a redesign of its compact lines in 1974.

[5] Along with a major reduction in exterior footprint (sized between the Vega and Monza in length), the X-body platform was adopting the transverse front-wheel drive layout used by its competitors.

In contrast to the fastback coupe and hatchback and the four-door sedan of the previous generation, the downsized platform was to offer multiple designs specific to each division.

While the Chevrolet Condor was originally intended for a 1978 model-year release (to compete against the Ford Fairmont and the smaller Dodge Omni/Plymouth Horizon), its launch was postponed into early 1979.

[7][6] Though design work was completed, company parts supplies and tooling were not yet ready to match the production of a vehicle replacing the Chevrolet Nova.

[8][10] Though closer in size to the Honda Accord than the Dodge Omni/Plymouth Horizon, the three-door and five-door hatchbacks proved popular, accounting for nearly 85% of sales.

The high demand for the model line, coinciding with a second fuel crisis, left GM with significant shortages of the standard 2.5L engine, with some customers waiting several months to receive their vehicles.

For 1982, the Chevrolet Cavalier (J-car, subcompact) replaced the Monza/Vega, offering coupe, hatchback, sedan, and station wagon designs.

[17] Intended to draw attention away from previous safety recalls and quality issues,[17][18] the Citation II was only nominally changed from 1983 (distinguished by decklid badging revisions).

Along with a new steering wheel, the dashboard accommodated a horizontally-mounted radio (a change necessitated by GM's adoption of standardized head units with electronic tuning in nearly all of its vehicles).

The year before, GM began to wind down its use of the X platform, as it dropped the Oldsmobile Omega and Pontiac Phoenix (the slowest-selling variants), leaving only the Citation II and the Buick Skylark for 1985.

The Pontiac-designed 2.5L "Iron Duke" inline-4 had been introduced in 1977 for the Chevrolet Vega and the rest of the H-platform, but it underwent a series of upgrades for it to be used in a transverse-engine chassis.

While less powerful than the Camaro Z28 (and later Monte Carlo SS), the Citation X-11 would also take over the role of the similarly sized Chevrolet Monza.

At its 1980 launch, the chassis of the Citation X-11 was upgraded with front and rear stabilizer bars and a retuned sport suspension, which were kept throughout its production.

For 1981, the X-11 was powered exclusively by a "high-output" version of the 2.8 L V6; a higher-performance dual-tip exhaust system raised output to 135 hp/165 lb-ft of torque.

Alongside the alloy wheels and tires, the X-11 featured a trunklid spoiler, sport mirrors, body skirting, and side striping.

In 1981, to better distinguish the model from standard two-tone Citations, the side striping of the X-11 was replaced in favor of large "X-11" door graphic, which remained in use for the rest of its production.

While produced without the front bench seat seen in the launch of the Citation, the interior of the X-11 was most widely differentiated with the use of a sport steering wheel.

[22] Like the other X-body cars, there were numerous reports of the Citation locking the rear wheels upon braking, causing loss of control and a crash.

[24][25] The X-body cars (which included the Citation) were the target of an unsuccessful lawsuit by the U.S. National Highway Traffic Safety Administration (NHTSA), which cited a tendency for the vehicles to lose control under heavy braking, and power steering problems.