Coupe and convertible body styles join the sedan version of Pontiac's best-selling car for 2006. G6 shares architecture with the Chevrolet Malibu and the 9-3 from GM-owned Saab. G6 sedans seat five. Coupes and convertibles seat four. The convertible has a power-retractable metal hardtop with a heated glass rear window. Sedans offer 1SV and base models with a 167-hp 4-cyl engine. Base V6 sedans and GT versions of all body styles have a 201-hp 3.5-liter V6. GTP versions of all have a 240-hp 3.9 V6. G6s come with a 4-speed automatic transmission; it has a manual shift gate in GT and GTP models. A 6-speed manual transmission is available for GTP coupe and sedan.

ABS and traction control are unavailable on 1SV, optional on base models, and standard on other G6s. An antiskid system is a GTP exclusive. GT and GTP have a sport suspension. Front side airbags are optional on convertibles. Front side airbags and curtain side airbags packaged as a single option are available on all coupes and sedans except the 1SV. Optional for sedans is a "panoramic" sunroof with a tilt-up front section and three rear-sliding panels. Available features include power-adjustable pedals, leather upholstery, OnStar assistance, and remote engine start.