lift the ecotec plastic cover off and you will see 4 in a row simple....and the spark plug i use with great results is an NGK 7956 BKR5EK,,,,THIS IS FOR A VAUXHALL ZAFIRA 199 TO 2005....AFTER THAT THEY HAD A FACELIFT......HOPE THAT HELPS.....PS...APPLY SOME LIGHT LITHIUM GREASE TO THE SPARK PLUG THREADS TO HELP THEM GO ON AND TO GET THEM OUT IN 2 YEARS TIME...AND REMEMBER ONLY USE YOUR HANDS TO INSERT THE SPARK PLUGS....ONCE SECURE ENOUGH THEN USE THE BAR AS NORMAL TO THE CORRECT TOURGE....TIME TAKEN TO DO THIS JOB..........25 MINS..HAVE FUN - Ben, Bonnyrigg, Scotland
Ben Crawford, November 2009