My car's idle seems to have a mind of its own. Sometimes it would run up and down and shake hard, sometimes it will just run up and down a little and shake a little less. I had the dealer check it three times already, they basically just run the codes and told me to f&&( off. This is a car I bought new with 12 miles in December, do you guys have a fix for it? I heard ground kit helps out a lot, what kit do you guys recommend? Also how do you adjust the idle on these cars?