My mothers snapped on her focus the other week, a year after having a new belt and kit fitted by rapid fit. the bill came £850 to fix it, but she didnt have to pay, they took responsibility, although they did try to get her to pay for the parts and wave the labour charge. ford say that black top zetec belts should last 100k or 10 years, silver top 50k miles or 5 years, but as they guy at ford told me, thats not set in stone, its just a guideline