- Confirm fitment by model code, year, market and original lamp type — not just model name.
- Ask which CANbus adapters, decoders or load resistors are included, and whether coding is needed.
- Judge optics by a wall beam-pattern photo with a sharp cut-off, not by product renders.
- Order one sample pair per platform before committing to volume.
Aftermarket LED headlight assemblies are one of the most profitable upgrade categories for distributors and workshops — and one of the easiest to get wrong. A lamp that looks perfect in a photo can still arrive with the wrong connector, a beam pattern that dazzles oncoming traffic or a housing that fogs after the first car wash. This guide covers what experienced buyers check before placing a volume order.
1. Confirm fitment down to the trim level
Model and year are not enough. Many vehicles change headlight connectors at facelifts, between halogen and factory-LED trims, or between markets. Before quoting, a good factory will ask for:
- The exact model code and year range (for example Audi A6 C7 2012–2015 vs 2016–2018).
- Whether the original lamp is halogen, xenon or LED.
- The target market — EU, US, GCC, Australia and Asia often differ in side markers and wiring.
- A photo of the back of the original lamp and its connector.
2. Plug-and-play is a promise — verify it
Plug-and-play should mean the lamp connects to the factory harness without cutting. In practice some vehicles monitor bulb current via CANbus; LED loads draw less and trigger warnings or hyper-flash. Ask whether the assembly includes load resistors, decoders or adapter harnesses, and whether any coding is required.
3. Look at optics, not just styling
Projector quality determines the beam. Ask for a beam-pattern photo against a wall at 10 m showing a sharp cut-off line. Check colour temperature (around 5500–6500K is typical), lumen output per side and whether the DRL and turn signal animations are configurable.
4. Sealing and heat management
Condensation is the most common warranty claim. Quality assemblies use a continuous butyl or silicone seal, breather vents with membranes and an aluminium heat sink or fan for the LED module. Ask how lamps are tested — burn-in time, water spray and heat-soak tests reveal weak seals before shipping.
5. Compliance for your market
Road legality depends on the destination. E-mark (ECE) approval, DOT/SAE marking or local certifications may be required for on-road use; many tuning products are sold as off-road or show items. Discuss documentation with the factory before ordering and label products accurately for your market.
6. Packing that survives freight
Headlight lenses scratch and mounting tabs crack easily. Insist on individual foam moulds, corner protection and double-wall cartons, and ask for drop-test results if you ship via courier.
Ordering checklist
- Send model, year, market and connector photos.
- Order one sample pair per platform.
- Test fitment, beam pattern and warning lights on a real car.
- Agree on packaging, labels and warranty process.
- Scale to mixed-SKU volume orders.
If you want us to check fitment for a list of vehicles, send it through the inquiry form — we reply with matched part numbers and a sample plan.
Need help with your range? Send us your vehicle list or browse our led headlight assemblies.
