The placebo effect is what I suspect is happening. And i think i can help
hondo has offered to loan me a magnet array for testing. Considering my wife drives around 300 miles a week, I can put these magnets on the fuel line without her knowledge and simply continue to monitor the results. I also drive the car, just not as much as her, so I'll be able to tell if there is any change. And I also have a scanguage, so I'll be quite capable of giving decent results.
And yes, this thread is indeed gripping