Thanks Rocket36 - i think am being extra cautious not to damage the car

Ended up fixing a Viofo A119 V2 ($135, CPL filter + GPS), for $80 at Strathfield Car Radios, Liverpool - neat job, took 2 hours.
It was hardwired with Viofo HK3 kit ($25). Parking mode works fine.

Ran the cables for rear camera though, Blueskysea B1W ($55) myself. It was easy, as there is a rear 12V socket in trunk that gets energised while you start the car.

If you need to do both front & rear for a dual ch setup, they charge $150.