Hi Vegemite, I'm looking at getting an aftermarket head unit for my 2016 Kluger.
I have already made inquiries about this with a couple of retailers, & they all told me that the unit I have chosen (Pioneer 8850BT) will work with the factory camera. Maybe all you need is an adapter for yours.
I will need a replacement aerial for the FM/AM, & there are wiring harnesses for the steering wheel controls, although the volume & track seek buttons will definitely work, but they are unsure about the phone "Answer" & "Hang-up" as well as the voice control button.
How did you go with your steering wheel controls?