In recent years car manufacturers when developing new car designs have paid great attention to two main aspects. On one hand there are the pollutant emissions and in particular the carbon dioxide emissions which are directly connected to the fuel consumption of cars, on the other hand there is the always increasing safety level required for the cars, with a particular attention to the safety of pedestrian and other vulnerable road users (VRU).

The present paper reports some results of a recent research activity developed in this perspective and specifically devoted to the design of a bonnet for a middle/low segment car. A global overview on the different solutions which can be used to obtain a lightweight and pedestrian safe bonnet will be illustrated.

The main part of the work deals with the design of a hybrid metal/plastic bonnet. All the aspects examined during the design of a new bonnet will be taken into consideration, starting from the technical performance and going through the manufacturing and economical aspects.

Then some considerations on a bonnet with a peripherical frame solution will be presented. At the end, the study on a further concept of hybrid bonnet characterized by a particular wire design of the inner structure will be addressed.