z tube is easy to take in and out and cheap to buy so no big loss if you changed your mind. Honestly I like the sound of the engine better with the stock intake tube on but the Z tube is much louder / deeper and still sounds pretty good. Probably put my OEM intake back on once I get my coupe muffler on the car.

get ya some used take off revised Z springs and shocks and struts to lower it down. Great ride height and I haven't had any issues with alingment.

oh and thankfully my car doesn't rattle

 

z tube + coupe mid pipe + hks muffler sounds really good....its a bit loud of you're looking for a lexus luxury car feel, but definitely belongs with a sport sedan. I have the exactly setup with an addition of crawford plenum and it really growls. There is some drone at low RPMS, and since I always drive by myself so the drone isn't as bad. But once you have some load (uphill, passengers) on your car it drones pretty significantly. I guess thats something to consider.

 

From tons of experience, go with the Injen, most of my forum members (g35nyc) started out with z-tubes and pop chargers, or stillen intakes, in the end most ended up getting the Injen CAI, sounds a lot deeper, looks the best IMO, and everyone thinks it feels better than any other intake.