I had the same results in my 03 5AT sedan. I sold my GG 10 wire kit the next week. I got a lot of crap from people when giving my honest opinion. I think the only one that respected it was Gord

 

I bought and installed a Gound Fusion, 11 wire kit about3 months ago. The response seem sharper, transmission shifts smoother, my idle is consant instead of slightly fluttering. After I installed mine, I reset the ECU. I love the way the car responds now compared to the way it was before the grounding kit.

Just to make sure I was not imagining the difference, I took the wires off the battery connection and drove it. I definitely noticed the difference when I re-connected the wires back to the battery ground. I can not really describe the difference other than if just feels sharper across the board.

 

I would have to say the same. I just experienced stronger response or more consistency in the cars performance with an HKS grounding kit on my 04 AT coupe. Car would idle quicker and overall electronics remained strong in the cold *** Chicago winter.

 

I think it has to do with loads placed on the battery and alternator. Also the temperature (read: your local weather) has alot to do with how a battery performs. But it never hurts to have a well-grounded electrical system, whether it adds noticeable performance gains or not, IMO.