The Wikipedia entry on Hudson is here, and information about Hudson's styling direct or Frank Spring is here. Examples of Hudsons from each model year that body was used are shown below.
Here is the completely restyled Hudson for 1936.
Hudson's 1937 facelift was minor -- mostly affecting the grille and the trim on the sides of the hood, though the wheel cut-out on the rear fender was also revised.
For 1938, Hudson featured a completely redesigned grille along with minor reshaping of the hood. As can be seen, a new grille treatment is an effective means of "freshening" an old body design. Pretty cost-effective, too.
The same areas were facelifted again in 1939, but now the front fenders were redesigned too. One reason was that, to keep up with the styling times, Hudson needed to drop detached headlights and integrate them into the fenders.
Again, changes to the front end to keep up with the competition.
Mostly detail changes for the front of 1941 Hudsons. But this time the rear of the car got some attention. Shown is a bustle-back design with different rear fenders.
The main changes for 1942 were smaller rear wheel openings and the reshaping of lower door and nearby panels so the the running board was hidden; this too to keep up with the times.
Hudson had a total redesign in the works for 1948. Its 1946 and 1947 models were nearly identical, sporting a new, partly sunken grille to distinguished them from the 1942s. These cars look a lot different from the 1936 models, but crucial points of similarity remain. These include the windshield and forward part of the top, the doors and the directions they open, and most important, the carriage-style side tuck-under towards the lower part of the sides. These details are difficult to face-lift.