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. The bonnet stay rod is a sturdy metal rod (often with a rubber sleeve which stops it rattling against the bonnet when the car is in motion) which functions to prop the bonnet open and hold it in place.
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, and an inner panel which is strong and offers protection to the engine beneath. The bonnet usually works with a latch mechanism. It is held down by a latch which stops it from opening unexpectedly whilst driving along and also acts as a lock. The bonnet can be opened from the exterior, by releasing the latch, hidden just under the bonnet lip, or by pulling a small lever inside the car, which is attached to the bonnet pull cable, which causes the bonnet to pop open. The bonnet can then be propped open and held in place by the bonnet stay rod.
The bonnet stay rod is usually held into the bonnet by a clip or grommet and attached with a hinged mechanism. The other end of the bonnet stay rod can be fixed into place in the engine compartment (some models are bent in the shape of a hook) so that the bonnet can be opened fully and held up, firmly supported by the bonnet stay rod.
If damage occurs to the bonnet stay rod or it has simply seen better days and come to the end of its functioning life, buying a bonnet stay rod will ensure you get the right part for the make and model of car.