To understand the various designs, first review some basics.
Most cars are divided into 3-box style and 2-box styles, with up to four “pillars” (A, B, C & D) also called posts. Pillars/posts are simply the supports (not always strictly vertical) around the vehicle windows.
Let’s see how we can understand various car designs now.
Coupé – Two door, fixed roof, seating for two people. In some models a squeezed rear seat can be present. It can be a 2-box style or a 3-box style.
1940s BMW coupé
1990s Honda Civic coupé
Sedan: This has got many sub types.
The unqualified Sedan denomination refers to a passenger car with 4 doors, 3-box configuration, 3 pillars (A, B, C) and each of the 3 boxes is distinctively used for Engine, Passenger and Cargo.
Subtypes
1. Notchback Sedan: In this the roof is parallel to the ground.
There is a sharp transition from one box to another.
The A and C boxes are generally longer and distinct. There is no smooth transition.
2. Fastback Sedan:
This is a 2-box sedan with a continuous transition from Box B to C.
3. Hatchback Sedan: this is similar to the Fastback, but here instead of sloping downwards, the back is lifted.
Station Wagon – This is a 2-box style car with 4 pillars. You can imagine it to be a sedan with the roof extended completely up to the rear end.
Hatch Back – Similar to above but with 3 pillars. You may know this car – a Maruti 800.
SUV – Sports Utility Vehicle: This is similar to the Station Wagon, with a difference in the chassis, which is based on light trucks. The vehicle is very rugged overall.
Crossover – As indicated by the name, it is a cross of features from both the SUV and the Hatchback.
There is another difference between Crossover and SUV.
An SUV’s construction was based on trucks where the body was assembled to a ladder frame. A CUV is constructed like a car, using unibody construction.
Unibody
Body-on-frame
Finally,
Convertibles: These are the ones with retractable roofs!
Please note: Some companies bring up their own definitions and styles mostly for the marketing and PR purposes. There occur modified definitions of some of the above (especially some type of sedans) depending on location and also the manufacturer.
The above was intended to providing a basic idea on the classification of various body styles.
Sources: Cars by Body Style, Category & Type
Images from Wikipedia Sport utility vehicle, Three-box styling
Pillar (automobile)
Car classification
THANKS
Courtesy: Raj Arjit
Udit Prasad 