The following video issued by BMW explains how some parts of the car are produced using the Water Cooled Press technique. This procedure allows for a considerable reduction in weight but whilst retaining the properties needed for a particular application.
In the tool and plant engineering facility at the BMW factory in Munich so called water cooled press methods are developed. These cooled press tools enhance the safety of the car and decrease CO2 emissions because the lighter material. Have a closer look at the process.