Hey, just got a g37x not too long ago.
She's going to be my everyday, going out, lookin' good, go to work, travel, everything car for the next 5-6 years. I want to do minor performance mods. Of course it'd be great if anybody could suggest the best results via the most economically friendly parts/brands. I'm thinking exhaust system for better sound, maybe increased horsepower/torque/fuel efficiency; cold air intake; and any other tunes/mods that may help me. I am completely newb at this and would appreciate any advice or feedback. Thanks!
p.s. she is a sedan, 2010, automatic..i know, lame.

But she's my multipurpose everyday car nonetheless~

 

Welcome to the forum.

The answers ye seek may be found by querying the mighty oracle, which resides beyond the "search" function.

I will, however answer you in the following post.

 

First off, bolt on mods like the ones you're describing have minimal (<40hp boost) even if you get all of them. Exhaust will change sound, high flow cats will change sound and power depending on if you resonate them, headers are typically seen as not worth it, Stillen gen 3 intakes are popular cold air intakes, and the motordyne upper intake manifold is a popular mod. A tune is a pretty good idea once you finish all your bolt-on's. Honestly, none of those are really cost effective. The best $/hp ratio would be via forced induction.

Mods that increase horsepower will decrease mileage, so you probably won't get both.

 

I dunno about lame, I have a 2010 X sedan 7AT and love it. Looks good, rides nice, plenty quick and does everything I need it to do although I sometimes wish there was more trunk space.

GFN was spot on with his advice, as usual, probably not going to get both power and mileage so you'll need to decide what's most important to you. Hotchkis sways and Fast Intentions resonated high flow cats made the largest and most noticeable improvement for me. I've also added a R2C intake which produces less power than the Stillen but I like the sound qualities a bit more. I have a Fast Intentions cat back exhaust being built, hopefully the 18 inch resonators will give me the sound I'm looking for. I also upgraded my brakes which, to me, made an immediate difference but really wasn't needed. Aesthetically I like it a lot better with Akebonos on.

Anyway, that's what I've done. I'll be adding a Motordyne at some point then getting her tuned. Check out the build threads, the DIYs and other threads. There a lot of information available here to help guide you through your process.

Welcome to the forum and happy modding!