So, Ford and Firestone have finally made the break. On 21st May Firestone and its parent Bridgestone announced that they would no longer supply Ford with original equipment tyres in North or South America. They were prepared to maintain supplies in Europe and Asia, but this only accounts for a quarter of their turnover with the world's second biggest automaker, and in view of the very public nature of the bust up it would seem most unlikely that Ford will keep Firestone at the top of its favourite suppliers' list. Neil Mullineux re-traces the steps in the break-up and assesses its consequences.