The 05/06 systems are fixed due to requiring a tune specific to the 05/06 computer code.[/QUOTE] So, not to be contentious, but this unit is not actually "tunable" in that it is fixed. I guess I was mislead by the advertisment/name. I was considering purchasing this unit over others because the fact that I believed it was tunable made it more appealing than other "fixed" units. Perhaps a more accurate product description would be in order?