The vehicle identification number (VIN), engine and transmission codes are located on the manufacturer's stickers located under the cover on the right side of the air intake compartment (see illustration 1), in the service book, as well as in the spare wheel well or on the bottom of the luggage compartment. Note: On station wagon models, the manufacturer's sticker pasted into the service book is located in the spare wheel well, and the sticker that remains in the car is located under the rear seat.
The engine and transmission numbers are also indicated directly on the units themselves: see Chapters 2, 6 and 7. The VIN is additionally stamped on the rear bulkhead of the engine compartment. The VIN number consists of 17 characters, its decoding is given below in the example:
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12-17 |
| W | A | U | Z | Z | Z | 8 | E | Z | 1 | A | # # |
1-3 Vehicle manufacturer designation: WAU - Audi AG
4-6 Filler characters
7-8 Model code: 8EC - Audi A4, 8ED - Audi A4 Avant, 8HE - Audi Cabriolet
9 Filler sign
10 Model year: 1 - 2001, 2 - 2002, etc.
11 Place of manufacture
12-17 Ordinal number
1. Sticker with vehicle data. 1 - VIN; 2 - Model code/Control unit code from the manufacturer; 3 - Model name; 4 - Engine power/Emission standards/Transmission; 5 - Engine and transmission code (for some countries not specified); 6 - Paint code/Interior trim codes; 7 - Additional equipment codes; 8 - Kerb weight/fuel consumption/toxicity data (for some countries not specified)
[The text is based on materials from the website AudiManual]