Actually I do have factory NAV that is projected over the Speedometer. When a call comes in, the radio is interrupted, the radio screen says "incoming call" and the voice says "incoming call, press the u-connect button to connect ". After pressing the U-connect mirror button the call goes "live" through the factory speakers and the radio head simply says "phone".

Got this working in my SRT-4 after collecting info from multiple forums and crawling ebay for parts. Have a few extra parts if anyone is looking for them. Also got this working with my NON-Nav REV radio. At first I had trouble pairing but then I realized you just needed to walk through the voice prompt setup via the UConnect button for the phone to see it and sync over bluetooth.

https://od.lk/d/MjRfMjc2MDc3M18/0105151936.jpg

You also have the option of something like this as well...

In Dash Radio Car DVD GPS Navigation for Jeep Grand Cherokee Chrysler Dodge RAM | eBay

I'm considering something similar for my 300m.

For me OEM or nothing. Also from experience these Chinese units are clunky and faulty. Fm reception sucked in the one I had and it had horrid input lag.