Z3's have pretty ancient suspension architecture, I wouldn't say your car will never handle as well as one because they don't handle that well in the first place.

Everyone gets new wheels that are huge and heavy, I would avoid this at all costs. 19 inch wheels will look nice, but they eat up HP, and that's something G35's cannot afford to lose.

Give this list a try:

Engine
-Motordyne Spacer, 5/16" or 1/2" ~ $250 new
-Motordyne Aramid Gasket ~$50 new, it installs under the lower plenum and dramatically reduces heat soak, I noticed a huge difference after buying it
-Smooth your lower intake collector and grind down the front runner to MREV2 specs, some people gain a little whp from this, and it's a free mod if you do it yourself!
-05/06 Revup Airbox (only the 6MTs have it) ~ $60 used
-HFCs/Test Pipes, make sure you get something good, price varies
-Motordyne or Stillen cat-back, go for a used stillen and throw in an x-pipe if you can't find or afford one of the last motordyne vq sedan exhausts
-Tune: Uprev, or other, find out if you have an early ECU sedan. If you do, you're out of luck with Uprev, but you can use Technosqaure or AAM. I am also working with Hypertech to get their programmer working with the early ECU cars

Suspension
-Revised 350z suspension, coils might cost too much for your budget, I got a revised suspension from a 350z for $150 with 10k miles
-Motordyne Sways, or any decent set of sways
-Replace your lower control arms (compression rods)/press out the bushings if they're failing, it will make a big difference
-Replace failing swaybar endlinks
-Get a good set of tires

I have OEM 16s on my car, and when I installed the coupe OEM 17s they were a LOT heavier, the car felt noticeably slower. If you're going to do wheels, get something light. People always say, "Go for the OEM 19s, they're light," but they forget to include the additional weight of the 19inch tires. Many people also get wheel combos that increase the overall diameter/circumference of the setup past stock specs, and this effectively makes your gearing longer, your speedo inaccurate, and your car slower.

You seem to be on the right track in terms of exterior mods, at the every least paint your lowers.

Good luck!

 

^^
Great post except that (at the risk of starting a big rim tangent) going with larger diameter rims doesn't necessarily mean larger diameter combination; my 19s with tires are actually a bit smaller overall than my OEM sport 17s.

 

You can absolutely get bigger rims and stay within the stock specs, but many people don't take notice. OEM 19s can absolutely fit within the stock diameter spec.

I love quoting this thread:
https://g35driver.com/forums/tuner-d...ms-dyno-3.html

I kept the coupe 17s for like 3 days, then I sold them. They were SO heavy, especially the rears. Even the tech who installed the tires on my OEM 16s was surprised how heavy the 17s were when he was removing them.