Plastic which is light in weight, dynamic and strong is improving the performance of cars in terms of fuel efficiency, safety and style. Since plastics are light in weight, though they are used for 50% of the car parts, they only make up for 10%-12% of the total weight of the car.
Since this reduces the total weight of the car, it also increases its fuel efficiency by 5%-7% resulting in substantial savings and lesser carbon emissions.
Plastics are used in various sections of the car. First of all plastics can be used to fill up the hollow space between the windows of the car, its bumpers, frames and door panels. Plastic foams fill up the structure of the car and at the same time do not add weight to the car. Body panels that are made of plastic absorb five times more energy than aluminium or steel and hence are helpful in absorbing energy when there is a crash. When plastic is used between two layers of glass it creates a wind shield that is resistant to shatter and thus helps drivers to see more clearly. Plastics are now used in headlights too to in order to make them shatter resistant.
More and more automotive manufacturers are using plastic paint film which is thicker than conventional paint by 15 times and provides more resistance to UV degradations, scratch and chips and at the same time retains a high level of gloss.
Other car parts where plastic is used are the housings for the braking and electronic system, interior safety parts of the car such as seat belts, plastic fuel tanks made of polyethylene which is highly dense and electric and hybrid batteries.
Source: http://www.intelligentplastics.ca