i think this is the right section for my question, which is... Where should i install my sub/amp to keep the handling of the car the same, or possibly better?
install it in the stock sub location(weight is added towards the center of the car, or in place of the spare tire(weight is added to the rear)?
it will probaly be 1 10 inch sub.

 

One 10" plus a box in place of spare and tools will probably close to stock weight.

 

hehe i have an answer! i'm psycho enough to put my sub box behind my back seat because it theoretically puts more "existing" weight towards the center of the car. can't exactly do that with a Z though, so...

haven't people done some nifty setups under the rear structural brace thing? (giant brace right behind the seats).

regardless, its a minimal detriment closest to the center of rotation, and lowest in the center of gravity. for my g35 sedan = ghetto 10" box behind the front seats on the floor (i'm stripped in the back anyway). but, i still refuse to give up good tunes!

i think the choice that makes most sense for you is a small box in the sparetirewell. a carbon-kevlar box and 10" would yield no weight gain from the spare and tools. $$ though. i don't like how fiberglass sounds, no matter how thick the resin. an mdf box should weigh more then the tools you are removing. choices choices.

phil