17 characters that can save you a lot of trouble
How many times have you ordered a part that "fits your model", only to discover it does not actually fit? The connectors are different, the bolt spacing is off, or the part is simply too big or too small. Frustrating, right?
Well, there is one simple way to avoid 90 percent of those problems. It is called the VIN. Vehicle Identification Number. Seventeen characters that uniquely identify your car and all of its specifications. When you use it for buying parts, the chance of getting it wrong drops to a minimum.
The VIN is not a mystery. It is a string of characters with a clear structure, and every character carries specific information about your car. Once you know how to read and use it, buying parts becomes far more precise because you know exactly what you are after from the first attempt.
What is a VIN?
The VIN (Vehicle Identification Number) is the unique identification number assigned to every vehicle at the point of manufacture. Think of it as a personal ID for a car. Every car in the world has its own VIN, and it is never repeated.
The VIN has 17 characters (a mix of letters and numbers), and each one carries specific information about the vehicle. It is not a random sequence. It is a coded description of your car.
Here is what a VIN contains:
- Characters 1 to 3 (WMI) - World Manufacturer Identifier. Tells you who built the car and in which country. For example, "WAU" means Audi, Germany. "WBA" means BMW, Germany. "VF1" means Renault, France.
- Characters 4 to 9 (VDS) - Vehicle Descriptor Section. Describes the model, body type, engine, gearbox and equipment. This is the most important part for buying parts because it gives you the exact specifications of the car.
- Characters 10 to 17 (VIS) - Vehicle Identifier Section. Year of production, factory, and serial number. Useful for pinning down the exact year and production batch.
Where to find the VIN on your car
The VIN is stamped in several places on every car. Here are the most common locations.
On the windscreen
The easiest spot. The VIN is stamped on a metal plate visible through the lower left corner of the windscreen (looking from the outside). Just stand in front of the car and look at the lower left corner of the glass.
On the driver door jamb
Open the driver door and look at the edge of the body (B-pillar) or the door jamb itself. There is usually a sticker with the VIN, paint code, permitted weights and other technical data. Bonus: you will also find the paint code you need for body panels here.
On the vehicle registration document
The VIN (officially called the "chassis number" in many European countries) is recorded in your vehicle registration document. This is the easiest way to find it without even leaving the house.
On the engine
On some models, the VIN is also stamped on the engine block. It is less accessible, but it can be useful for verification.
Why is the VIN so important when buying parts?
Here is a concrete example that illustrates the problem. You have a "VW Golf 5 1.9 TDI, 2007". Sounds specific enough, right? Well, no.
A Golf 5 1.9 TDI from 2007 could have a BKC, BXE, BLS or BRU engine. Each of those engines has different components. The alternator for a BKC engine might have a different bracket than the alternator for a BXE engine. The ECU is definitely different. Even the turbo can vary.
The same goes for other specifications. A Golf 5 from 2007 could have a 5-speed or 6-speed manual gearbox, or a DSG automatic. It could have air conditioning or not. It could have ESP or not. Each of these variations affects which parts fit.
When you give the VIN, all of these details are clear. The VIN unambiguously defines which engine, which gearbox, which equipment your car has. No guessing, no "maybe it fits". Either it fits or it does not, and the VIN tells you that upfront.
How to use the VIN when buying used parts
Here is a practical process that should become your standard.
Step 1: Write down your VIN
Save the VIN in the notes on your phone. You will need it every time you buy a part, so keep it handy. Double-check that you copied it correctly, because one wrong character can mean completely different specifications.
Step 2: Decode the VIN
Use an online VIN decoder to find out the exact specifications of your car. Free decoders like VINdecoderz.com or ETKA (for the VW group) give you all the details: engine, gearbox, equipment, year of production, even the paint colour.
Step 3: Include the VIN with every request
When you are looking for a part at a scrapyard, online, or through PoDi, include the VIN whenever possible. A serious seller will use that VIN to check the part is compatible with your car. On PoDi, when you send a request for a part, there is a field for the VIN. Use it whenever you have it to hand.
Step 4: Compare VINs
If you are buying a part from another car, compare your VIN with the VIN of the donor car. Ideally, both cars should have the same engine, gearbox and relevant equipment codes. This minimises the risk of incompatibility.
VIN vs. OEM part number
Besides the VIN, there is another important number you should know about: the OEM part number. This is the number the manufacturer assigns to each individual part. Think of it as a serial number, but for the type of part, not the individual piece.
For example, an alternator for a Golf 5 with a BKC engine has the OEM number 028 903 028D. An alternator for the same Golf 5 but with a BXE engine has a different OEM number. If you know the OEM number of the part you need, buying is almost risk-free because you know exactly what you are looking for.
How do you find the OEM number? A few ways:
- On the part itself - most parts have a sticker or stamped number
- In your car's service documentation
- Using a VIN decoder that can give you a list of all parts and their OEM numbers
- Ask your mechanic - if the old part has been removed, the number should be on it
- The ETKA catalogue for the VW group, or TecDoc for all brands
Common mistakes around the VIN and part identification
Here are the mistakes we see most often, and how to avoid them.
Relying only on model and year
"I need an alternator for an Audi A4, 2010." That is not enough. The Audi A4 from 2010 comes with at least five different engines and three gearbox types. Without the VIN or at least the engine code, the chances of getting the wrong part are huge.
Copying the VIN incorrectly
One wrong character in the VIN can change the engine model or the year of production. Always double-check the VIN you send to the seller. The best approach is to photograph it and send the picture.
Ignoring facelift models
Many car models receive a "facelift" mid-way through their life cycle. A Golf 5 from 2004 and a Golf 5 from 2008 can have different parts even though both are "Golf 5". The VIN clears this up because it contains the year of production and the series.
Assuming "same engine equals same part"
The same engine in different car models sometimes has different peripheral components. A 1.9 TDI in a Golf and a 1.9 TDI in a Passat can have different connector layouts, brackets or hoses. Again, the VIN is the answer.
Online tools for checking the VIN
Here are some useful online tools that help you decode a VIN and identify parts.
Free tools
- VINdecoderz.com - basic decoding for all brands, free
- NHTSA VIN Decoder - a US service that works for most brands
- Carvertical.com - also offers vehicle history (partly free)
Specialised tools
- ETKA - the official parts catalogue for VW, Audi, Seat, Skoda. The gold standard for part identification in the VW group
- TecDoc - a universal parts catalogue covering all brands. Used by professionals across Europe
- RealOEM.com - for BMW, an excellent free parts catalogue with diagrams
Tip: if you are buying parts for the VW group (VW, Audi, Seat, Skoda), ETKA is an absolutely essential tool. Enter the VIN, and you get the full catalogue of every part in your car with OEM numbers, pictures and schematics. That eliminates any doubt about compatibility.
Practical tip: make a "personal ID card" for your car
Here is something I recommend doing once and using forever. Make a note on your phone or a piece of paper with this information:
- VIN number
- Engine code (e.g. BKC, N47D20, K9K)
- Gearbox code (e.g. GQQ, JLU)
- Paint code (e.g. LA7W, 475)
- Year and month of production
- Engine power in kW
With this information, buying any part becomes trivial. You give the data to the seller, they find the exact part, and that is that. No guessing, no returning wrong parts, no frustration.
Why the VIN becomes your best friend
The VIN is your ally when buying used car parts. Seventeen characters that significantly reduce guesswork and help you get exactly the part you need. Remember it, write it down, use it for every request.
When you send a request through PoDi, the VIN is one of the most valuable pieces of information you can provide. With it, suppliers can quickly and accurately identify which part you need and send you a matching offer. Without it, more guessing remains, which costs both money and time.