Looks like a 4 is more likely than a 6. Motor Trend:
"The big difference relative to the OPC is replacement of that car's 2.8-liter turbocharged 321-horsepower, 321-pound-foot V-6 with a higher-output version of the 2.0-liter turbo that's expected to produce at least 255 horses and 295 pound-feet. That abundant force is routed through a six-speed manual to a Haldex all-wheel-drive system that includes an electronically controlled limited-slip rear differential. Why ditch the six? According to Craig Bierley, product marketing director for Buick, that engine would likely incur a gas-guzzler penalty, and in any case, the design brief was to build a car that could accelerate to 60 mph in the fives, and the 2.0T was easily able to accomplish that while achieving considerably better fuel economy than the V-6."
Read more:
http://www.motortrend.com/auto_shows...#ixzz0c3pSrDJw