The bonnet is a crucial part of the car body, for beneath it is housed some of the most important components a car needs in order to run. In most cars the bonnet is the hinged cover that protects and allows access to the engine compartment.
Often made of steel, bonnets are also made of aluminium, fibreglass, dry carbon and carbon fibre. The bonnet is fixed to the frame at the front of the car and, with the action of hinges, opens outwards. A bonnet is made up of an outer panel which is designed to be smooth and streamlined, assisting with the aerodynamics of the vehicle, contoured to match the shape of the car, and an inner panel which is strong and offers protection to the engine beneath.
Many car owners choose to fit bonnet insulation in their vehicle. bonnet insulation primarily helps to reduce the noise produced by the engine. Bonnet insulation absorbs both noise from the engine and the road before it reaches the inside of the car. Bonnet insulation comprises of foam rubber which has aluminised polyester or a woven material, such as felt, on one side and an adhesive tape on the other side to apply it to the bonnet. The bonnet insulation is mounted on the underside of the bonnet and produces a significant reduction in noise levels.
Worn out, mouldy or damaged bonnet insulation should be replaced with bonnet insulation that will be compatible with the make and model of car bonnet.