I've used it on my wife's Regal GS. The stuff is awesome! Just be warned that it will smoke worse than a freight train for about 1/2 hour after you suck it in through the Vacuum port. You might want to consider doing it out side of city limits.
After I used it on the GS you could tell it made a difference if you punched it. It just seemed a little more peppy than usual. Though, I would hold off on using it on your solstice for a while.