LINDSEY RACING - Your Porsche Performance Parts Center: BOSCH WR7DC SPARK PLUG - SPBOSCHWR7DC
Amazon.com: Bosch WR7DC (+1) - Spark Plugs Nickel - Set of 4 : Everything Else
Amazon.com: Bosch WR7DCX (+21) - Spark Plugs Nickel - Set of 4 : Automotive
Spark plug Bosch WR7DC for 520/4+520i all years of manufacturing, you need 4 for 1 car and for 525+528 up to 08/1976, you need 6 for 1 car | Wallothesch
BMW Spark Plug Bosch WR7DC+ - 12129062594
New Vintage Bosch Spark Plug WR7DC 7900. | eBay
Amazon.com: Bosch WR7DC (+1) - Spark Plugs Nickel - Set of 4 : Everything Else