Spark plug Bosch W8DC for 518 from 07/1975 up (518 LHD 4625659 / 518 RHD 3820624) and for 518i+520/4+520i all years of manufacturing only for country version AUS, S, you need 4
Sparkplug Bosch W8DC - original BMW - 12121276283, 12 12 1 276 283, 1276283, 12-12-1-276-283
Spark Plug for Mercedes - Bosch W8DC - Non Resistor Type