 Such cars include the Astre (based on the Vega), the Acadian (based on the Chevette), the Sunburst (based on the Spectrum), the Firefly (based on the Sprint), the Tempest (based on the Corsica), the Sunrunner (based on the Tracker), the Pursuit (based on the Cobalt; later badged as the "G5 Pursuit" and simply "G5"), and the Wave (based on the Aveo; later badged the "G3 Wave" and "G3").Pontiac engineer Clayton Leach designed the stamped steel valvetrain rocker arm, a simplified and reliable alternative to a bearing-equipped rocker.This design was subsequently picked up by nearly every OHV engine manufacturer at one point or another.