[LightningGSX]

Electricity flows from bumping valence electrons from atom to atom.Its kinda hard to visualize, but electrons have a negative charge.So essentially they are transfering lower potential from - to +, and electricity flows from higher to lower potential, so electrons move from - to +, but the charge flows from + to -.A while back, I suspect car makers had the same confusion, since at one time vehicles had a "positive grounding" scheme.

On a side note, waste spark systems like ours, the secondary technically isn't grounded.It fires from coil to sparkplug to head to sparkplug and back to the coil.Thats why grounding the head isn't critical as it is in some vehicles.