Then Kenwood DMX820WS perfect fit unit goes into the Perodua Myvi AV G3 (pre facelift model)

The Kenwood 200M wide series head unit always looks perfect in the Perodua's and Toyota's. Installation of these units are all pretty straight forward as it is very unlikely you will face mounting issues. The bolt pattern matches up perfectly.
The only challenge you may find is in retaining things like steering wheel controls and reverse cameras. Even then it is usually not a problem if you know where to get the necessary adapters and such. If you are looking to get these adapters, check out the links below.
The Kenwood DMX820WS is equipped with Apple CarPlay and Android Auto, however, for this particular model, it is still wired. For Wireless applications, check out these other models.
DMX9021S - https://www.fasmoto.com/kenwodd-dmx9021s
DMX8521S - https://www.fasmoto.com/kenwood-dmx8521s
DMX7522S - https://www.fasmoto.com/kenwood-dmx7522s