The 1984 Nissan 300ZX replaced the 280ZX that was starting to show its age despite strong sales. The traditional style was becoming dated and its basic engine design originated in the 1960s. Plus, other Japanese manufacturers were introducing fresh competition, such as the Mitsubishi Starion, the Mazda RX-7, and the Toyota Supra.
The 1984 Nissan 300ZX was about as different from its predecessor as it could be. The original rounded contours and scoop headlamps were replaced by a wedge profile with semi-concealed headlamps. A potent 3.0-liter V-6 replaced the classic inline-6. source