Why do all of the Porsche cars look the same?
 

Examine the rear ends of the sports cars: the 911, Boxster, and Cayman. They are very different. The 911 has an air inlet grill in back that neither of the other cars have. The Boxster uses one central exhaust; the 911 and Cayman each have two (the 911s are wide-set; the Cayman's are close together). The Boxster only comes as a convertible. The Cayman only comes as a hard top (coupe). Now, compare Vag com 15.7 any part of any or all of those cars to the Cayenne SUV. They could be made by different companies.

The new Panamera sedan has a rear end unlike any of the small two-door sports cars. Its front somewhat resembles a 911, yet the hood is entirely different because there's a motor up front in the Panamera and not in the sports cars, which have their engines in back.

All car makers try to design "brand identification" into their GM Tech 2 cars, so that you can tell from a glance who made them. The most obvious visual cue is the logo - like the large "Ford" oval; however, other cues are used throughout the lines. Ford is a good example: many of their older and larger cars have rounded lines and use oval elements in their dashboards. Newer Cadillacs are all angular (They all look alike to me).