Recently bought a SC Base Z and I am extremely pleased with the car and performance. I was wondering what the ride is like w/18 rims and what can be done to improve the ride and make it a little less bouncy over road imperfections ( everything is stock )?

I have been in a touring model as well and the ride was the same..is it mainly because of the limited wheel travel or the spring rates could be a little more progressive and improved with after market kit? Just curious if bigger rims and or wider tires will help any or changing out springs or buying adjustable shocks will make it a little better without sac in handling. Im sure the G35 coupe rides a shade better..any thoughts?