FYI: I have a 2004 350z enthusiast w/ 17in. tires....overall, I love the car. The only complaint that I have is that the ride is bumpy, jittery and overall pretty rough...is there any way to improve the ride comfort?
Thank you in advance for your feedback!

 

A softer spring would help with the ride. The car is meant to ride rough, its a sports car, not a luxery car. Because of this it has a stiff suspension. If you want a softer ride you need to give up performance.

 

Look up threads with "Koni" in it.