Especially to compete with the Ford GT, Dodge Viper and other American sports cars/grand tourers?
From my archived, now-deleted question:
The modern Pontiac GTO was a luxury grand tourer rather than a true "muscle car" like the GTO of the 1960s and '70s. The 400 hp 6.0 LS2 version is my favorite. 40,745 'Goats were produced between 2004 and 2006 (including the 350 hp 5.7 LS6, both of which were based on the Chevy Corvettes - C6 and C5 respectively). GM only built 27,994 Chevrolet Corvette C6 Z06 cars. Stock (including its BFGoodrich g-Force T/A KDWS, 245/45ZR-17 95W M+S tires) it could do a Car and Driver-tested 0-60 sprint in 4.7 seconds and quarter-mile sprint in 13.3 seconds. Top speed is 155 mph with the limiter and 189 without it (<<< oh yes, I've done that at Volkswagen's Ehra-Lessien track in my 2005 back in January '06 when the 'Goat was still in production - no kidding!). It has a 0.31 drag coefficient and 23.7 square foot frontal area, equating to a 7.3 square foot drag area.
Added (1). It was Pontiac's version of the base Corvette. It was 4 mph faster than that Corvette!
Added (2). By the way, I was talking about production Pontiacs, not racing Pontiacs like the Promod.