Some of the information in this manual applies only to cars of a particular model year or range of years. For example, ?1999 m.y.? refers to the 1999 model year. The model year does not necessarily match the calendar year in which the car was manufactured or sold. To be sure of the model year of a particular car, check the vehicle identification number (VIN) on the car. Technical changes made in production within a model year are identified in this manual by listing the VIN for the first car produced with this change.

The VIN is a unique sequence of 17 characters assigned by Audi to identify each individual car. WAUCB88DXVA169020 is an example. Each of the 17 letters and numbers indicates certain facts about the car and its manufacture. VINs used to distinguish information in this manual may refer only to the last eleven digits?the characters 8DXVA169020 in the example above.

Your Audi's VIN can be found on a plate mounted on the top of the instrument panel, on the driver"s side where the number can be seen through the windshield. The 10th character is the model year code. The letters ?I?, ?O?, ?Q? and ?U? are not used for model year designation, for example, ?X? for 1999 m.y., ?Y? for 2000 m.y., ?1? for 2001 m.y., etc. This manual covers Audi A4 for the model years 1996 through 2001. The table below explains some of the various codes in the VIN numbers of models covered by this manual.