Not everything needs to be digital and “smart.” License plates, for example:

Josep Rodriguez, a researcher at security firm IOActive, has revealed a technique to “jailbreak” digital license plates sold by Reviver, the leading vendor of those plates in the US with 65,000 plates already sold. By removing a sticker on the back of the plate and attaching a cable to its internal connectors, he’s able to rewrite a Reviver plate’s firmware in a matter of minutes. Then, with that custom firmware installed, the jailbroken license plate can receive commands via Bluetooth from a smartphone app to instantly change its display to show any characters or image.

[…]

Because the vulnerability that allowed him to rewrite the plates’ firmware exists at the hardware level­—in Reviver’s chips themselves—Rodriguez says there’s no way for Reviver to patch the issue with a mere software update. Instead, it would have to replace those chips in each display.

The whole point of a license plate is that it can’t be modified. Why in the world would anyone think that a digital version is a good idea?