One way to see if your car has free supercharging is to pull up the charging screen. On the bottom right corner of the screen there should be a section called Previous Supercharging (or something like that, I don't remember the exact wording). In that section, if it says no previous supercharging (or something like that, again I don't remember the exact wording), then the car has free supercharging. If you do not have free supercharging, that section would list your previous supercharging activity along with cost.