GSX package (mid-year): front & rear spoilers, hood-mounted tachometer, hood/side stripes, Rallye Ride Control (H6), power front disc brakes, 4-speed, G60x15 billboard tires on 7-in wheels, Rallye steering wheel & instrumentation, black bucket-seat interior (trim 188), 3.64 posi

Years 1965–70 Models 3

Also described as Riviera GS optionGran Sport option, $306.38: 360 hp Super Wildcat dual 4-bbl (engine code **LX**, chromed twin-snorkel air cleaner, finned aluminum valve covers), modified exhaust & TH-400, posi w/ 3.42 axle, ornamentation, wheel coversRiviera GS option (dealer ordering code): performance axle/posi, ride-and-handling chassis, ornamentation; 1970 listing verbatim "Riviera GS Option"

Documented applications

Full-Size — LeSabre / Electra / Wildcat

1970 Confirmed

Riviera — see [riviera.md](riviera.md#year-1966)

Riviera

1965 Confirmed

Riviera; 3,354 built
1966–1970 Confirmed

Riviera; verified on 1970 factory full-size sheet; 1965 usage confirms continuity

Skylark / GS

1970 Confirmed

GS 455 only; $1,196 pkg; 678 built (491 Apollo White code 10, 187 Saturn Yellow code Q); 400 w/ Stage 1

This page aggregates every documented appearance of A9 in the Buick reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.