Anyone ever use it? My buddie used it a couple times and used to hit fuel cut in the 4th and 5th gears. I heard it has something to do with being below sea level like I am here in South Florida. Is this really bad for our cars? Also Cobb states to use only Sunoco 100 octane, but the Sunoco that sells 100 near me here has a bad rep for having bad gas. Their 100 oct is more like 98-99. There is another gas station near me selling 100 octane and has a good rep. Any suguestions? I just downloaded the 100 oct map, and want to give it a try.