Crash test eggies

We were at the end of the forces topic and i was looking for a single lesson to do some momentum consolidation before moving onto the next topic. I started thinking about an egg drop type experiment to get across the idea of Force = rate of change of momentum but instead was passed a great idea to do crash tests with an egg sitting in a seat on and old trolley car. The kids were given a car with a single eggbox as a seat and they had to protect it as i rolled the cars down a 45 degree 2m long slope into a brick wall. Below are a couple of the brilliant crumplezones that the kids made i especially like the one that has a sail to presumably reduce the momentum in the first place - thinking outside the box.  One group even had air bags ( crumpled up paper protecting the egg.) It helps if you have rotten eggs as there is a real need then to protect them - one group saved all the eggs, one group were perhaps feeling a little bit more like destruction as they had no seat belts for poor mr egg who proceeded to fly into the wall or even worst in one crash he got stuck between the crumple zone and the wall.. Poor Mr egg!