The cars in question are the Audi 80 Fox (1972-78), details here, and the Volkswagen Passat / Dasher (1973-81), Wikipedia entry here. The names "Fox" and "Dasher" were used in America for marketing purposes.
The Audi design is a clean, classical 1970s "three box" theme featuring large amounts of glass. The main aesthetic flaw so far as I'm concerned is that the wheels are too small.
The VW version is a 5-door "hatchback" with sail panels providing a fastback feeling. I'm not certain of this, but it looks like the backlight windows are the same for the Fox and Dasher, keeping costs down. The only other visible differences besides the sail panels and fifth door are the brand symbol ensembles on the grilles.
Although styling was basically well done, I wasn't totally pleased with my Dasher (yes, I actually bought a 1974 model) due to valve problems in the motor.
I owned a '74 Dasher that looked like the ones shown in the first two VW photos.