Can you be held responsible if your son crashes with another car on your private property?

yes.......usually only thing private property has to do with claims investigations is make it more difficult, as no police report will generally be written......if your son is negligent and liable for the loss, he is....private property or no........on your property or not.......if he is negligent, he is negligent and will be liable (you as the gaurdian) for the loss........more info is needed for me to help.......facts of loss...your vehicle or another? who owns vehicle? permission or not to drive? etc....