I am giving the car back into my indy tomorrow, but the spark plug sign has never come up on the service info display in the dash before. its not on the key but shows when i go into the service info menu. He has serviced the car before and also services the wife's VW and is pretty good. When he hooks it up to his laptop there is no option to remove the spark plug sign. Also as a diesel car surely my car should not even be equiped to show this sign! Will see what he says tomorrow.