That is the SAM (Special Alfa Module) which recognizes the underfoot sole and determines if it has been throttling 4C's over time. If it determines that the right foot has over "X" miles over "X" cars it will automatically reduce the minimum requirement for that pilot. I know, the Alfa Engineer told me.It’s close. My Tributo unlocked at 172 miles - likely before but that’s when I tried and it went into dynamic. I think it’s 300km / 180 miles technically.