Yeah so, having most of the single player campaign completed, I decided to try my hand at the endurance race which sets you up at Sebring in a 2016 #66 Ford GT Le Mans race car for 81 laps. Lol, man when I was half way through I was like oh man why, why did I do this to myself! Hahahaha
Good thing though is that I went up 7 or 8 XP milestones and unlocked a bunch of cars and got enough credits to plop down on the One-77 - the special car among a few others that are only available from the Speciality Dealership.