Always look for well-known brand names such as Bosch, Delphi or Ferodo. Many original-equipment (OE) parts are dual-branded with the car and parts manufacturers logos, so you can identify who made the existing part on your car and seek a cheaper alternative.
Many manufacturers of parts for vehicle makers routinely sell those same parts on the aftermarket. These are produced on the same production line, but are often stamped with only the parts manufacturers logo.
For example, the NGK spark plug used in the Mk VI Golf shown in our example is exactly the same part as the original VW-branded product, but it works out at almost 1 cheaper when bought via Ebay. A matching quality Bosch plug sold by a high-street retailer costs almost a third less than the original-equipment part.
Parts makers labelling components matching quality have to certify that their component is made to the same technical specifications as the original part, so always ask to see this certificate.
There is very little official regulation of parts quality, but some components such as brake pads, shoes and linings are covered by a European Regulation 90 safety standard. Never buy a brake friction component unless the part and packaging carry the 90R E-mark.
If youre unsure about a parts quality, dont buy it. If youve already paid for it, ask your dealer or garage to check it for you before they install it. Good garages will never fit a poor-standard part to your car, no matter how much you press them, so make sure you choose a reputable workshop.