Silly question, but I’ll ask it anyway.


Just wondering, but can you make an interconnect with spark plug wire?

why is or isn’t this done?
last_lemming
I spend most of my time in the future. I only come back here for the jokes. Besides, they don’t have audio forums in the future. The trolls got too out of control. 
You could do it. It would probably sound awful with most spark plug wires.  Most spark plug wires are highly inductive (and resistive) stainless steel wire around a core that may or may not be conductive carbon. I guess if you like your music really warm, you may like them :-)
Most domestic vehicles use spark plug wires with a fiber glass core covered in latex graphite, which provides between 10,000 and 12,000 ohms of resistance per foot of wire.  But this varies with wire type   

Do you really want to put all of that resistance in the signal path???

https://youtu.be/FpPBxN_FzmA
Not very well if the wire is of type 1) distributed (carbon core) or 2) fixed resistor.  They have more resistance than copper to reduce RFI interference.  It does not matter at 100,000 volts in the car but it does in an amplifier.
I am not aware of any fixed resistor in ages, and copper, not in forever except for racing, and even then you want to control the spark to prevent fuel cavitation.
Most domestic wire is not simply a fiber glass core covered in carbon filled latex. Most are variable spaced fairly high resistance stainless wire. They variable spacing is so they can have consistent performance independent of wire length, hence why today you buy vehicle specific wire sets (or should).
Don't pick some random site on the web for your information. Most mechanics won't have a clue about the inner working of spark plug wires.