The second year is comprised of a single season of racing that spans a two month period. You will be greeted with a 'Congratulations' screen upon completion of the final championship race of your second year. It will show the season-wide statistics for the number of events you completed, total distance driven, credits earned, and experience until your next driver level. Pressing 'A' will unlock the achievement and advance you to the event selection for Year 3.
My second season was comprised of 24 races.