Does the 2023 Tucson L need chassis armor?

There's no need to do that. If it doesn't break down after 12 years, you wouldn't want to drive it anymore. It's outdated.

It's recommended to apply a coating in coastal areas, preferably have it done at a 4S dealership.

Not necessary.

I did it, I did the whole set.

The 4S dealership said it's not necessary to spray.

It might get better if you spray it, but I didn't spray it. [grinning face]

If you're driving on country roads, you might consider adding protection to prevent small stones from damaging the chassis. But if you're mostly on asphalt roads, the original plastic guard should suffice.

Rust never sleeps.