Replacing letter/number combination on front left or right side panel (330i xDrive Wagon, 328d xDrive Wagon, 330i GT xDrive, 340i GT xDrive)

WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2019 BMW 340i GT xDrive, 2019 BMW 330i xDrive, 2019 BMW 330i GT xDrive, 2018 BMW 340i GT xDrive, and 2018 BMW 330i xDrive. However, it is still accessible from the selected car via links, so may be relevant.