One of the selling points of Volkswagon beetles, apart from the low cost, was that the style didn't change much from year to year.  North American auto makers brainwashed a surprising number of people into thinking that there was something wrong with them if they didn't buy a new car at least every 3 years. Changing the looks every year was part of that, to make older cars obvious by their appearance, even in regions such as Florida or California where cars did not corrode from road salt.