Where is the best place to get them from either standard or after market not sure how much is out there or if the make any difference at all. It's just a while back I had a misfire in cylinder 1 I solved the problem by switching the spark plugs in cylinder 6 and 1 but it came back the other day not sure if its the same thing but I did use a not as high quality fuel as I normally do (95 ron instead of 99) and the exhaust seems to gurgle so I'm looking at swaping te plugs and egbition coils out see if that resolves the dash light that appears now and then (usually goes out wen I turn the car on and off)