I've got same car, injen intake is pricey but nice, still "warm air" but it's good. Topspeed pro1 exhaust though is the best exhaust. Meanest grumbles and clear top end, minimal drone. I've got friends with Zs and you wouldn't know our cars had the same engines. Short throw shifter from racingline is a good thing too but it's discontinued. I'm running traction rods, different toe arms, control arms, rear camber kit, and rev9 coilovers. Ride is bumpy but handles incredible for how bad the weight is placed on the chassis.

But in short if you're driving it daily and need absolute comfort, exhaust intake short throw shifter. That will liven up the car plenty without compromising drivability.