I have the hyper ground on my Crossfire and well first off it was a pain to install as you need to daisey chain the ground wires around the engine compartment and there isnt alot of places to bolt these to.
As for did it do anything no But i wasnt expecting it to.I installed it as more of piece of mind I am an aircraft Engineer and airframes have ground wires all over so what the Hay .
So i figure what can it hurt it will only reduce the RF feed back you get when you have alot of electrical components working together ( you may notice this as a wine in your stereo speakers from your Alternator.
If any one thinks it will give HP then we may as well all be putting stickers on our cars and dont forget to Grease the muffler bearing