: Turn your car ignition to "Accessories" or "On" to power the head unit. Insert USB : Plug the drive into the unit's OTG USB port .

: Manufacturers generally advise against updating if your system is already stable, as it offers little visible change and high risk.

Spreadtrum/Unisoc provides the (also called UpgradeDownload) freely for authorized service centers, but it has leaked to the public. Combined with official firmware packages from device OEMs, the update process is 100% free .