I was discussing my bounce problem with a guy who already owned a new tiburon and was in the process of buying a new Z for his wife. I was telling them the only thing I didn't like was the bounciness on certain roads.
The guy told me he had the same problem with his tiburon but after he put this JT double wing spoiler on it the problem went away. He said he thought the down force of the wing nullified the bouncing.

Anyone out there with a Z and large heavy spoiler that can confirm this will fix the problem?

 

Would you put one on if it did?!

 

I also experience the "bounce" effect, but only on certain roads. It could be alot better compared to other sports cars I've been in but at the same I did see a e46 m3 experience to what appeared from the back a bouncy ride, but not as severe as the Z can get. I've been planing on modify that suspension on the Z before even taking delivery (11/7/02), so it doesn't really matter to me, just need to buy it sooner then later.

 

Unless his rear wing is HUGE the downforce at "normal highway speeds" is very small.

As for heavy, if you just want weight back there you can put some weight in the trunk (a sand bag) to test your theory.

 

or throw a couple cadavers in the back.