Mileage , condition and fully documented service history are in my opinion the main criteria in how quickly a specialist car like the ISF will sell . These are rare specialist cars with a very very small buying / selling market . Those who want one will know what they want . Trying to persuade people to come from historical brands like Mercedes , BMW and Jaguar is very tall ask . So if it ever comes to parting with your ISF prepare yourselves for a wait . Hopefully nobody will buy and you can keep enjoying this great highly underated car .