Hi. I am going to change the spark plugs on my 2006 GT. After looking at lots of different ideas on the internet, I would like some current information. Some say leave the engine cold, others say warm it up. Some say put in Ford plugs, others Champion, etc. Should you soak the plugs after you break them loose, or is that not necessary? Also, if the car runs fine, is there any benefit to replacing the coils? Thanks.