I can tell you from personal experience that grounding kits are far over rated. I added one to my 95 talon TSi AWD and found that really all it did was keep my head lights from dimming with the stereo up and evened out the idle alot. As far as power... not much if any difference. You definitely don't need to buy a "pre made" kit though if you're interested in doing a ground wire kit. Its definitely not a bad idea... but don't spend $50 on one. Go to home depot, buy some 8 or 4 gauge wiring and some terminal ends with loops, and redo the main ground (off the battery to the chassis) and then go from there and run grounds to every metal surface that has a bolt. If you have any further questions feel free to ask. This is something I may be doing this weekend, if I do, i'll post pics of where and things of that nature.