I have a 1997 XJ6 with relay covers in the engine compartment held down by a spade fastener that is locked in place with a small nylon block which are missing. I cannot identify or find these in any of the common fastener sites and do not even know what to call them. Can anyone help me?

Thanks in advance,

 

They are a quarter turn nut (Jag part number AGU2643) and are available from Jaguar Classic Parts - part labelled 7 in the attached diagram.



For a small piece of black plastic they are very expensive!