The affordable roadster that was meant to help save Pontiac fell short in a number of ways, mainly due to it being rushed to production.
The poor Solstice, and for that matter, poor Pontiac. The Solstice was a fantastic idea and a great design, but when it came to execution, it left something to be desired. The Solstice was the car which was to save Pontiac, and if different economic conditions had allowed for a bit more development work, it probably would have. But despite all of its promise, the reality of the Solstice is that it never quite achieved sports car status, no matter how much we wish it had.
By the early 2000's, it was hardly a secret that Pontiac was dangerously close to being completely irrelevant. The brand got a bit of the public spotlight in 2001, but as this was mostly the result of the debut of the Aztek, that wasn't an entirely good thing. So the folks at Pontiac were working hard to bring out another new model which would remind people that it was something more than the maker of what is possibly the world's ugliest vehicle. This would actually very quickly lead to the Solstice, with a concept debuting in 2002, a production version debuting in early 2004 and the first cars hitting dealerships in 2005 as 2006 models.
That is tremendously fast for an entirely new car to go from idea to metal, but it was a rather urgent matter. It was this rush which would create the real problems for the car. The idea was to make an affordable mid-engine roadster, something American car companies haven't exactly been known for, but on paper it looked like they had it exactly right. But with the enormous rush to bring the car to market, it ended up being a giant hodge-podge of GM parts-bin engineering. Sharing components with other vehicles doesn't necessarily doom a car to failure, but in the case of the Solstice, there wasn't enough time to get all of these components to play nice with each other.
There is always a lot of talk about how the Solstice was underpowered, but this isn't exactly the case. People forget that roadsters aren't muscle cars, and huge horsepower numbers aren't what they're about. The 2.4-liter engine's 177 horsepower had 2,888lbs to pull around, and this isn't outside the bounds of normal for a roadster. The current Mazda MX-5, the yardstick by which all modern roadsters are measured, has a power-to-weight ratio only a bit better than this. No, the problems with the Solstice were bigger than this, as a lack of power is really a pretty easy problem to solve.
Part of the problem, thanks to the parts-bin construction, was that the car had a truck transmission, out of the Chevy Colorado, and this was ill-suited for duty in a sports car. Driving dynamics in general were pretty hit-or-miss, with some aspects turning out surprisingly good, but others not so much. In 2007, the GXP was rolled out. This was a version with a 2.0-liter turbocharged engine that produced 260 horsepower, and there was a dealer-installed option to take it up to 290 horsepower. GM also quietly replaced several of the problem components in the name of installing better go-fast parts, and the GXP really does qualify as an actual sports car.
The Solstice would actually have a fair amount of success in SCCA club racing, and the problems with it really weren't all that difficult to sort out. The car's flaws weren't the kinds of things that were inherently wrong with the design from the start. They came from GM's rush with it, and were there to have been a second generation, the problems would surely have been ironed out. But as it stood in 2009, Pontiac had a range of irrelevant rebadged cars and one dud roadster, so it was folded. It's a shame the Solstice didn't get a chance to evolve, but the decision to kill it was hardly surprising.