I'm guessing this is a Canadian 2.4 and more than likely has most options? 6000 Kilometer = approximately 3728 miles, which as you know is very low. Pricing is difficult because while it's basically a new car it also is a 10 year old used car. I'd price it between 15 to $17,000 (USA). However, at that price you're going to be competing against turbo GXPs w/moderate miles. If you're looking for a quick sale, then I'd price it between 12 to $13,500.
If this was mine, I'd be highlighting that it's low-mileage, a one owner car, that comes w/all service records and documentation. I'd also take a couple dozen pictures top up, top down, front, side 3/4 views, engine, and underbody. Honestly, there's no such thing as too many pictures when it comes to selling a car.
Also, the Solstice is a niche car, and it may take several months to sell, plus winter is approaching which isn't the best time of the year to be selling a convertible. You might want to consider advertising it on Hemmings since that publication is geared toward collectors and auto hobbyist. In real estate the saying is location, location, location, w/selling cars it's about exposure, exposure, exposure, so I'd consider listing it on Ebay w/no expectation of it selling. Good luck.
2006, 12,000 Miles, $15,500
2008, 17,026 Miles, $12,000
2007, 8,500 Miles, $15,995
2007, 6,000 Miles, $15,500