We're down to splitting hairs now. I know GM sort of phased in their new styles, none of which were as radical as Ford's (I actually prefer the '42-'48 Lincoln styling over the '49-'51s), but except for the stray early birds like Studebaker, for example, the big changes came in 1949.
Back when my mom was still single, she wanted a new car. The '48 models were still on the market and she wanted a Ford. Her friends told her to wait until '49 when the new style would be available, but she didn't want to. I remember that big green '48 club coupe being parked in my grandparents' garage when we'd go back to Chicagoland to visit them. They had it until 1967 or so. My mom had left it behind after she married my Dad in '49. He had just purchased a gunmetal blue '49 Ford, so she ended up with a '49 after all.
Stan -- the headlight bezels don't look the same on the '41 Chrysler.