2005 T4 CD/MFD Options

I have taken my dash apart and found the details of what is fitted, here goes;

- JBL CD/Tape Head Unit - Pt No. 86120-47120 (CQ-ES0370A)
- Multi Function Display - Pt No. 86110-47081

I noticed on the back of the MFD that only one connector is used (M13?) the centre one is not used and I believe this is normally for the Satnav version; and the last one that is also not used and this a 6-pin smaller connector... I don't know what this one is for though.

I'd like to replace these with ones from a later model and have seen several on various auction sites; my questions are...

1. If I fit a reverse camera in the space where the blank is, will my current MFD have the capability (resolution / software etc..) to accept a camera, or will I need a different model MFD?

I have seen later model MFD's with camera and more control buttons for Nav, but I am less concerned about SAT Nav as I have perfectly good TomTom.... If I plug in a reverse camera directly into whatever input pins I need too, will it display?

2. If I replace the CD head unit for one of the later Prius model head-units that plays mp3's, will it work or are they configured differently?
I've seen a reasonably priced CD unit Pt no. 86120-47240-1 which supports mp3 files... Is there anything else I would need?

3. Does anybody have the schematic or wiring diagrams for the head unit and/or MFD?

I guess I'm asking a lot but I don't want to to have to buy an after market unit unless I really need too... My basic theory is I shoud be able to fit a later model head unit, although I may need to alter the wiring of the car harness as the pin outs may be different.