New puzzler time!

Now, I don't want anyone to think that I'm ripping any puzzles off, because this one does bear a striking resemblance to the puzzler from last week! 
But I'm sure that's fine. As my brother would say, not a single person on this fair planet, including our own mother, would ever listen to this show twice. Certainly not twice in a row!
When I called the house, she'd say, "Ray who?"  She always liked Tom better!

Okay, the sort of new puzzler...

Some years ago.  Crusty old mechanic. Beat up, worn down Buick. Comes in. The engine is flooded. This is probably ringing a bell for anyone who read this last week! 
Anyway, the engine, it's flooded. I told the mechanic to look at the spark plugs. 
He said he wanted to try something. And he took all the spark plug wires off the plugs. He left them halfway on. Instead of taking the wires all the way off, as I said, he left a distance between the ends of the spark plug in the metal part of the spark plug wire. So there was a big gap where there had been a good metal-to-metal connection, which conventional wisdom tells us you need to get electricity to flow from one place to another. For example, you wouldn't screw your light bulbs halfway into the socket.

So he wants to try this. He turns the key, and it starts right up. Amazing. And when that happened in the garage, there was a chorus of, "Oooooh. Amazing!"
This was roughly 100 years ago that this happened. Over the years, we have had many opportunities to verify that this technique absolutely works. So empirically, we have proven that this works. The question I asked last week was, is this possible? Is it possible that this technique actually works? And the answer was, yes. 

But this week's question is, how is this possible?

What's going on here? I want the real technical explanation, please! You must have the real, scientific answer. We want the Carl Sagan worthy scientific answer to this week's puzzler.

Good luck!