Modular Car Radio with a Raspberry Pi + Touchscreen

[Symax]

I'm pretty sure there are other Raspberry Pi car radio projects out there, but I want to make sure at least the radio has the basic features of AM/FM radio and potentially a CD/DVD player as well as a (real time) clock.

Other potential features:

Backup camera
GPS with turn by turn directions (and potentially automatically set the clock time with timezone boundaries)
Auto dim and auto volume levels
Bluetooth pairing with many devices
USB port for flash storage and reading
Option to play DVD movies from flash drive or DVD player
Possibly a 5 CD/DVD changer (if one can be found)
Option via a Cell phone module for cellular data and/or voice
Possibly read OBD-II diagnostics
Some voice controls
Screw terminals supporting a multitude of car radio jack types.

I do realize that the majority of the space for a standard car radio could easily be taken up by that of a slit based CD/DVD player  For the containment size, so far I'm looking to standardize on the equivalent case size provided in the Ford Windstar since the Official 7" Pi touch screen is about that same size (unless a better touch screen is found).  At the moment I'm looking for feedback as to what components to include, and would prefer easily obtainable/standardized parts.  I do realize that creating a custom PCB for all of this is more than likely necessary.  I am aware that there are many other Single Board Computers are available besides the Raspberry Pi.  I personally am fond of the ASUS Tinkerboards myself.  The idea here is to balance cost, availability, and functionality all within one package.  At the moment, I'm leaning towards using the Raspberry Pi 3B+ as the base for this project.  I may be swayed to use a Pi Zero, but I do want enough computing power to handle all of the features.  I realize this project will require hardware development along with software development (I'm a fan of Ubuntu OS myself).

An example component I am looking for feedback on is the AM/FM chip:
https://www.silabs.com/products/audio-and-radio/multi-band-radios/si4822-26-27-40-44-radio-receivers

Based on the chart and datasheets on that page, I am considering one of the Si4826, Si4827, or Si4844 chips and am looking for feedback as to which one would be best in this application as I'm unable to discern any of the differences between them.

As for the modularity of this radio, I consider GPS, Cellular, Camera, Microphone, and possibly a few other non-standard devices to be optional.

As for tools that I have available to make this happen; I do have a soldering iron and a 3D Printer.  I do have a Toaster oven that I've attempted to convert into a reflow oven, but I have not used this since I built it.

As for the CD/DVD module, I want a slit based player and not a tray based player.  If you can help me find a source of this type, that would be great!

If you want to provide links to other similar projects, I'm willing to examine them.