Hi,
The head unit only protrudes (Good word) 10mm at the very most. If it were any tighter the flip out screen would foul when its all the way out, In real term the screen would not be able tilt back far enough for you to see it and might cover the satnav screem bottom and controls. It looks the dogs to me where it is, but you could fit the original surround if you like to smooth it out a bit more. I think your dash kit is like the 1 I had and all they did was remove the cheap lookin horrible pocket/tray thingy. I'm very particular
The other thing I had to make sure of was that when the screen was engaging it didn't hit the gear stick on its way in or out.
The Ipod draw just finishes it off neatly. Any Alpine stckist will have get you 1 of these the Code for it is KTX-550iD In dash portable media station. The are about £50.
Lastly the head unit alone won't imorve the sound quality. I dont know what you have installed, but the Bose amps don't work well with any other head units and you need to take out a tranducer from that or the satnav stops talking. It's not a job for the novice (not that I'm saying you are). Below is a list of what I ended up doing with mine.
The final solution to this needs to be based on what you want from your install. I've just had all the Bose stuff taken out of my car and replaced.
I wanted a totally steath install. The fronts were replaced with Hertz Hi-Enegy space components. The rears with Hi-Energy 2 ways colour matched cones to the car (Orange). The rears haves Hertz bar grills. The fronts and rear are driven by an Alpine V12 545 amp as most head units give up early on in the power game. This is mounted in the passenger glove box behind the seat with a 6 disc changer sat on top of it
I had an Alpine 10" sub mounted in the original place in the Z with a custom box built in around it and moves 13 time more air than the bose did. This is driven by an Alpine 1000Watt monoblock amp, Mounted in the bulkhead where the Bose amp used to be.
The Head unit is an Alpine IVA-310R 1din flip out mounted in the bottom of a dash double din converter and above this an Alpine Ipod draw to finish off the dash nicely.
If you're going for power Dynamat everything or you'll the interior will shake itself to bits. (Really).
I went for steath which limits your options and I wanted to keep my boot space (what little there is).
If you want more show then the world is you toasted muffin (dont like oysters).
My advice is find a great installer and talk alot about what you want before you start.
Regards.