It was already a known fact that, for the most part, dash kits aren't required for BASE 370Z due having a double-din opening. If you plan to install a single DIN unit, a universal dash kit is needed (for now until Metra releases a 370Z-specific kit) to cover the gap with a plastic cubby or even fill it up.
You're marching on uncharted territory when it comes to Bose-equipped Zs. It has always been a known issue with any Bose-equipped cars. I've not heard anyone not needing kits to replace Bose head units and speakers.
BTW, I would advise against using Bose speakers to your aftermarket headunit. The impedance of the speakers is most likely under 1 ohm, and it could fry your head unit. The only work arounds is an impedance matching transformer for the speakers or something from PAC or Schosche. If each speaker is driven with its own amplifier, you'll need to figure out the wire to switch it on.
BOSE = pain. It's not impossible... but requires more effort. Good luck! That's why I ordered a Base.
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