Things have changed, a lot. Comparing car advertisement in the sixties with today you can recognize a couple of significant differences. Text and explanations were much more important 40 years ago then today. You can find car ads from the sixties that barely used pictures but had long texts in small print to explain specific features or advantages. Today, this barely exists anymore. Today's car ads come with large and well done pictures (note, that the Mercedes from 1966 in the upper ad isn't even in focus!) and very little text and description. This makes a lot of sense, as anyway cars do not really differentiate on the technology and feature level anymore. When you read car comparison tests today the differences between the cars in the field are really small, be it performance, size or any other parameter. Equipment of cars is coming in quite standard as well, every car has ABS, ESP, electric windows, air condition and stereo, no big inventions need to be explained. The biggest difference is probably the price and there's not too much to say about this in an ad. And of course the car design is an important buying factor even if we think that all modern cars look alike.