Since your car rode well for the first three months with this setup I think your shocks need to be replaced. Another explanation could be that your springs settled and you're riding lower, which may or may not cause the change in ride quality

I just got my Ground Controls and Koni Yellows installed 2 weeks ago; still riding on the softest shock settings. I'm currently having some issues with ride quality on the freeway also, but I'm saving that for another post. Still, I think GC+Koni yellows are the way to go if you want affordable adjustability; many, many, many people are using this same setup and seem to be very happy.

On that note, if anyone can recommend a good setting for the GC+koni yellow combo I'd be happy to know. Right now when I hit bumps on the freeway (fairly large bumps) going about 65-70 mph, the car bounces really hard and bottoms out upon hitting the bump, and the force actually throws me up out of my seat My rebound is set to 1; I assume changing it would help this problem.

Another question: what are the spring rates on the GC's, and do these rates change with the drop height?

Shingo