In January I purchased a Fiesta, which came without a spare wheel. I then purchased a suitable spare and tyre from a local tyre retailer in the village, which thankfully has never been used. Today the car went back to the Ford Dealer for its first service. The very thorough mechanic came to see me and told me that my spare was only legal to use on one side of the vehicle because the tyre was 'directional'? Is this correct? Is it illegal to use a tyre against the directional arrow? Should I go back to the tyre retailer and demand that the tyre be replaced?