One brand that has used a consistent grille theme for nearly 30 year is Dodge, with its crossed bars or "gunsight" nested within the radiator opening.
This motif has been used on Dodge's trucks as well as its cars. But a few years ago the truck line was spun off as a separate brand called Ram. The name "Ram" was chosen because Ram was a line of Dodge trucks. Back in the period roughly from the early 1930s to the early 1950s, Dodge vehicles used a ram (bighorn sheep) as its hood ornament.
When the Ram truck brand was established, someone at Chrysler insisted that Ram would still be Dodge-related and the symbolism would be retained. A brave statement, that, but will it hold for the future as the Ram brand continues with its own staff who might not want to carry the Dodge symbolism for all time. Or might the Dodge people decide to let Ram retain the theme and have Dodge do something different? Are there any clues?