The Solstice comes in two trims: Base and GXP. The Base is powered by a 2.4-liter, 177-horsepower four-cylinder engine. The only transmission available is a five-speed manual or automatic. The GXP comes with a 260 hp turbocharged four-cylinder. The GXP also includes an electronic stability system, stainless steel exhaust outlets, sporty seats and changes in exterior styling.The base Pontiac Solstice is a carryover from 2006. A new trim the GXP is available for 2007.