Hey, my MkII 3dr had them on from the factory. I've also seen them factory fitted on Mk1 Mondeos.

On one side of the tyre you will find an elliptical field with 3 numbers. It might say "DOT" somewhere around it aswell. The first few figures are the week, the last figure is the year.

424 = 42nd week 1984

A triangle symbol prior to the figures means it was produced in the 1990's.

"triangle"424 = 42nd week 1994

And from 2000 on, there are 4 numbers
4204 = 42nd week 2004

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