I have an 06 G35 coupe 6mt that is stock. I am looking to start modifying it and am thinking of the following items in this order:
1) cold air kit--K&N
2) dual exhaust kit--stillen
3) front & rear strut tower bars
4) B&M Sport shifter
Any input would be appreciated if other brands/mods are suggested. Please advice. Thanks!

 

hhmmmmm how about the search button!

 

Gtrhipo . . . Welcome to the 'Driver boards. There is a mountain of information here and the modding topic is the mainstay, here. Your initial list of mods is a good one. Prior to installing any mod, you would be well served if you searched and read the many reviews and personal accounts of certain products.

It was quite confusing for me some 2 years ago when I first happened onto these boards. Consider your budget and where it is that you want to be with your modding venture. Through a bit of reading and diligence you will find yourself with a G that you will be proud of for years to come. You are off to an excellent start already . . . You are the owner of a fine car. Enjoy!

 

Don't do the shifter

 

What Andy said,and instead of the k&n cai,get the jwt popcharger and ztube,you'll see most have one of those.But search around,and just look for each item.

 

On the cheap (+/- $300) here are my suggestions.

If you want handling go for sway bars (I have Stillen), they will absolutely transform your car.

If you want looks, go for 15mm spacers all around. I wish I had pictures taken before my drop. On a stock suspension with the 19 inch wheels the spacers will give your ride a much more aggressive stance. It’s subtle, but people will start asking you if you have larger wheels and tires. Parked next to a stock G, yours will just look better.

 

Oh yeah, about your suggestions. The cold air kit is just a noise maker. You will not gain any power (proven time and time again with dyno results). But sound is part of the driving experience and should not be discounted. It also looks good when you open the hood at a gas station to check your oil.

AND MAKE SURE TO KEEP A CLOSE WATCH ON YOUR OIL CONSUMPTION!
Our cars have a tendency to burn a lot of oil.

Dual exhaust, you cannot go true dual without losing power. Assuming you go with a non-true dual exhaust, you will get a few horsepower. But to me, messing with the exhaust note is a sin.

Front and rear strut tower bars...just go with the sways. Driving with strut tower bars will make you think “I can kinda feel it around corners.” Driving the first time with sways, and taking a corner fast will make you think “I just wet myself.”

The shifter, probably a good idea.

 

get the nismo exhaust if you want the sound of stock but louder!

 

I'm not sure this is entirely true.
Ultimately, the Stillen CAI and Z-Tube probably won't add any power per say. However, throttle response may be improved by default as you will be removing unnecessary baffles in the intake system leading to the throttle body.

The Stillen TD is less restrictive than the stock system. Ultimately, this modification will add HP, albeit with a possible loss of torque way down low.
Overall, this mod really (TD exhausts in general) make the car sound a whole lot meaner and less like the rest of the FM dual outlet cars. Again, you need to choose the option which is most suited to your tastes.

The shifter is a tougher question. The stock setup is pretty solid. You may not want to mess with it. Additionally, if you think a lot of vibration comes through when using the stock linkage, well......

The Sway-bars sound like a fantastic idea !

You can see the mods I've performed. Overall impression:
Mid-range is much improved, this is where we saw the biggest improvement. -Top-End is much improved as well, just to a lesser degree. The improvements make the car that much more enjoyable to drive.
I had terrible gas in the car at the time of the dyno session. The car was detonating like a **** all week before the dyno and pinged on the dyno. Thus the tune may be a bit more conservative. I'd bet that with better gas I might pick up a few ponies.
Suspension is my next mod.