Pontiac Grand Prix
260-hp supercharged GTP/GT models and the 303-hp LS4 GXP made the final Grand Prix the most aggressive W3 expression.
Open guide →Platforms / GM W-Body / W3
2004–2016 ERA · ENTHUSIAST-FOCUSED
W3 / Third Generation W-Body
The final Master Customs W-body chapter focuses on the cars with genuine enthusiast value: supercharged 3800 Grand Prix models, LS4 V8 flagships, the LaCrosse Super, and the later 300-hp Impala powertrain that carried the architecture to the end.
Editorial focus: W3 is not a trim-by-trim commuter-car catalog. Master Customs goes deep on the variants with performance, engineering, modification or collector relevance. Base versions appear only where they provide important platform context.
ENTHUSIAST MODEL INDEX
The final W-body cars worth going deep on.
Four nameplates define the last performance chapter, with the LS4 V8 becoming the era’s signature hardware.
Buick LaCrosse
The CXS brought a 240-hp DOHC V6, then the 2008–2009 Super added the 300-hp LS4 V8 in a true sleeper package.
Open guide →Chevrolet Impala
SS models used the 303-hp LS4 V8 from 2006–2009; later 3.6L cars brought roughly 300 hp and carried the old W architecture through Impala Limited fleet production.
Open guide →Chevrolet Monte Carlo
The final Monte Carlo generation ended the nameplate with a 303-hp LS4-powered SS and one of the most unusual front-drive V8 coupes GM ever sold.
Open guide →HALO CARS
W3 performance icons.
These cars deserve direct-search deep dives instead of being buried inside general model guides.
260 HP SUPERCHARGED
Grand Prix GTP / GT
Series III 3800 supercharged performance.
303 HP LS4 V8
Grand Prix GXP
The most ambitious front-drive Grand Prix.
300 HP SLEEPER
LaCrosse Super
LS4 power with Buick restraint.
V8 SPORT SEDAN
Impala SS
303 hp and everyday usability.
FINAL MONTE SS
Monte Carlo SS
LS4 V8 in the final W-body coupe.
TECHNICAL CORE
Series III 3800 → LS4 → High Feature V6
- L26 naturally aspirated 3800 Series III
- L32 supercharged 3800 Series III
- LS4 5.3L front-drive V8
- 4T65-E / 4T65-E HD
- 3.6L DOHC V6 applications
- Later 3.6L direct-injected Impala powertrain
END OF THE LINE
Performance peaked before the platform disappeared.
By the late 2000s the Grand Prix, Monte Carlo and LaCrosse W-body all exited production. The Impala remained, with fleet-only Impala Limited production extending the architecture through the 2016 model year.
REFERENCE STANDARD
Master Customs prioritizes factory-era documentation and period road tests, then uses established enthusiast references for service and ownership context. Equipment changed by model year and RPO; verify a specific car by VIN/RPO and factory service information before ordering parts.