Early 1955 was the end of Aero-Willys in the U.S. Kaiser decided to stop production. However, the company found renewed life in Brazil.
Given the industry's then-usual three-year lead times for getting new designs production-ready, both Darrin and Grisinger likely targeted their facelifts for 1956, certainly no earlier than 1955.
Neither restyle would have been particularly expensive or difficult to tool. But in the end, there was no reason to push ahead with anything. In early 1955, Kaiser decided to give up building cars in the U.S. and to cast its fate with Jeep vehicles, which even then were spinning money as they do today.
But just as Kaiser found renewed life in Argentina (as the Carabela), the Aero-Willys found haven of its own -- in Brazil. Built by another Kaiser subsidiary, Willys do Brasil, it carried on through 1962 as a cleaned-up 1955 four-door sedan with Willys's old low-compression F-head six (to suit Brazil's very low-octane gasoline) and a strengthened structure (to cope with the country's poorer roads).
For 1963, famed Milwaukee-based designer Brooks Stevens applied handsome new square-rigged outer panels, and the car continued with few other changes all the way through 1972, first as the Aero-Willys 2600, then the Willys Itamaraty, and finally as the Ford Itamaraty (Dearborn having acquired Willys do Brasil via American Motors in 1967).
That's eloquent testimony to the Aero's sound original design. A shame it wasn't further evolved -- or more appreciated -- in its native land.