Once again, prototypes and older hawkwing jets are better for the races. Don't bother trying to win if a prototype is nearby, because you cannot get the extreme times necessary.
Honestly, it's not really fun for me anymore, since the modern vehicles have such useless boosts.
Edit: In fact, I think the MK2's are slower than the MK1's.
So once again, thanks, to the pancake heads who ruined vehicles.