The system does not always work because when my car was vandalised it sat for nearly 6 weeks because the garage found Mods on it. No one told me they were waiting but all my mods were declared and I am insured with Highway through Keith Michaels - soooooo - if you need to make a claim make sure you contact your insurance company asap to remind them you are on a modified car policy and get them to inform the assessor and garage too!!