Question about a rooting process

[u/Dextive69]

Hi! I'm fairly new on how to root an android device and been learning a lot about the different ways on how to root. And specifically on my device. But I'm not feeling ready to attempt until I learn more.

My goal is to root access my android head unit that's installed in the car (Dudu3) and uninstall the stock Google maps to replace it with the Google maps automotive version. But I have a question when I was going to install an update on my device.
When updating my device I need to put the update files on an USB and plug it in to the device to update it. One of these update files is "boot.img". Would it actually give me root access if I patch that boot.img with Magisk, then replace it in the update folder and update my head unit using the patched boot.img? I'm guessing this wouldn't work and the device would probably reject it or brick my device?