[Graham]

We're just going to have to protect the cars better because this will happen again.

One of the problems is weight, currently the box with cars weights just under 10kg which is manageable, if you increase it to 15kg then probably just about for one person, and if 20kg then definitely not practical for someone wanting to take it to the local post office. I  have seen some wooden boxes using 5mm plywood of the same size which are 7kgs in weight. Possibly reducing that to 3mm Plywood would reduce the weight but not recommended for external boxes of that size. Some some kind of internal liner or smaller case which fits inside the cardboard box seems more practical. I have thought of making the 5 foamed boxes out of plywood rather than as currently foam board but this gives us the same overall weight issue.