I was the first person to use it on a Mark VIII when it first came out years ago. I had a custom tune sent to me via email by one of the guys who have the full commando software to remove timing retard in between shifts and to adjust for the Cobra Intake with No IMRC's. The basic tune you can make is OK, it doesn't work very well on the 96 cars however, not sure if they worked out the bugs as I no longer have a 96 Mark VIII.