Perhaps swap existing screen for a detachable iPhone mount with quick release, like myriad old school car audio faceplates.
You retain all hard buttons for radio and aux, all that's needed to add to CarPlay 2.0 is helper app with decent GUI on top of terminal commands as HVAC control.
Like this:
What I proposed on the G8 forum was to have the huge iPhone 6+ permanently mounted behind buttons on left and right with screen flush (it is just a smidge too big) and of course blank filled with an adaptor plate as neat surround.
Essentially a commercial adaptor for easy slotting of complete handset. The battery and sim card and GPS and motion detector and customisability through Cydia make it the most capable head unit on the market.
This is the mount, US$99:
iPhone 6 slides in to the left on tensioner top first to allow perfect peripheral coupling of serial and analog.
Remove the LCD from the existing IQ unit completely, swap the iPhone+ directly in its place with the mount above.
Once the phone is mounted where the LCD used to be,
behind the plastic buttoned bezel, it'd be a matter of connecting to the HVAC controller as per the video and developing a decent UI on the iPhone to control the HVAC.
CarPlay iOS (versus the knackered version in some new cars as their main selling point) does a great job working with other apps, so I was thinking to build a simple "HVAC" app with a nice CarPlay theme and add it to the CarPlay home screen to make CarPlay via iPhone the true info hub.
I'm looking to keep it factory and as simple / versatile as possible, I think it' will be possible to fit with little or no mutilation of the "dash" components.
What are your initial thoughts
@TazzI