The tier list defines Class A cars as having 1 or more excellent traits and Class C cars as being below average in 1 or more such way. Formula 7's best top speed and racing ability makes it "excellent' in this area. If its poor wasting is what limits it to the 3rd class then shouldnt MASHEEN and El King also be Class C cars as they are the very worst at racing fullfilling the requirement to have this rating.
Requirements for Class A and C cars are very limited and contradictory