Prep or undercoated finishes: They are usually known as primers. The primers used for cars are usually grey or black in color and they are usually used as a base just before painting. The surface which is primed is porous and it is sanded before apply another coat of paint.
Base coat paint: they are usually the actual colored paint for the vehicle. After application of base color we need to harden it and provide it gloss because base coat lacks in both.
Acrylic Lacquers: This is used to provide the gloss or the shine to the vehicle. This paint has been discontinued by most of the manufactures but it is used for antique and classic cars.
Clear Coat: This coat of paint does not contain any color. It is used to give high gloss or shine to the paint.
Specialty paint: specialty paint are usually of two types, one for older cars and one for modern cars. It application totally depends on the car.