Almost every part on a classic Mercedes-Benz, BMW, Porsche, Jaguar or Land Rover carries an OEM part number — the reference the original manufacturer used in its parts catalogue. When you order a reproduction part, that number is the single most reliable way to confirm fitment. Here is the process we recommend to every customer before placing an order.
1. Find the number on the original part
Most interior trim, switches, covers and brackets have the number moulded or stamped directly into the plastic or metal, usually on the back or underside. Remove the old part and look for a sequence such as A 124 821 00 89 (Mercedes-Benz), 51 43 8 176 285 (BMW) or 911 571 348 01 (Porsche). Brush off dirt with a dry cloth — numbers are often hidden under decades of grime.
2. Know the difference between a part number and a casting number
Some components show more than one marking. A casting or mould number identifies the tool that made the component, while the part number identifies the finished catalogue item; they can differ slightly. If two numbers are present, the one that matches the format used in your car's parts catalogue is normally the part number. When in doubt, note down both.
3. Cross-check against your vehicle
- Chassis code first: confirm your model's chassis designation (W124, R129, E30, XJS, Defender and so on). Many parts look identical across generations but differ in mounting points.
- Left- vs right-hand drive: dashboard, console and door components frequently have LHD and RHD versions with different numbers.
- Facelift changes: manufacturers often revised parts mid-production. A 1986 and a 1992 car of the same model line can use different references.
4. Match it to the listing
Every part we list at CarPartClassicX includes the OEM reference numbers it reproduces, directly in the product title and description. Search the store by the number itself — for example 1248210089 — rather than by part name. Part names vary between catalogues and countries; numbers do not.
5. Still unsure? Send us the details
If the number is unreadable, missing, or you cannot find it in our catalogue, send us a part enquiry with:
- your vehicle model, year and chassis code (the VIN helps),
- the number or any fragment of it you can read,
- a photo of the part from the front and back.
Our workshop checks each enquiry against OEM reference information where provided and will confirm whether we can supply or reproduce the part before you commit to anything.
A note on reproduction parts
Parts supplied by CarPartClassicX are made-to-order reproductions, produced to fit the original vehicles and checked against the applicable OEM references. Marque names and part numbers are used for fitment identification only — see the disclaimer on each product page. Typical production time is 3 to 14 days, and shipping is free worldwide on orders over £99.
Browse all 32 makes or submit a part enquiry — and if you only remember one thing from this guide: order by the number, not the name.