I'm getting a 4000NEX mainly for the Carplay/HD Radio features. I will not be using the appradio stuff or anything like that. What cable will I need just to enable iPhone 5 functionality and Carplay? I'm hoping I won't need the HDMI stuff. Is it just the CD-IU52 cable and that's all?

Also am I required to use the Pioneer cable, or will any Apple lightning cable plugged into the USB1 work? Thanks in advance.

Purely for CarPlay then it's your standard USB to Lightning plugged into USB1 so we are led to believe. Obviously until it's released we won't know for definite

Don't bother with the CD-IU52, it's just an expensive cable that does nothing different than the one you get with your phone from Apple.

make sure its an OEM APPLE CABLE. All those knock offs wont work with the units

I have a clone, works perfectly

I have a PAC usb extension that mounts in my dash, where my cigarette lighter was(i removed the lighter). it is made for aftermarket head units and comes with a mount that can be screwed under dash, or in my case it fits where the lighter used to be. It is run to usb1, so i can just plug my lightning cable right into it, and it works great. I ran usb extension that came with head unit from usb2 to inside glove compartment, where i have 250 gb ssd with over 200 dvd's ripped to mp4 format. My advice is do not purchase Pioneer cables. There are several people who have used aftermarket cables, including me.