I will say, this race, at night, in 3rd person view will definitely CRUSH your framerate. I get a rock solid 68fps at all times, but this race destroys my computer.
But I can honestly say this, and I am extremely DEEP into the game... I've only raced that race one time in all my normal play (I've gone back a couple times since this thread just to check it again)... and it wasn't in 3rd person. So to try and wrap up the entire game into one race, when the game is 99.99% everything else, which for me is rock solid 68fps, seems silly. That one race is not representative of the game. It obviously has some kind of issue with it specifically that the devs need to correct. So in no way should anyone make a conclusion based on it alone.
Obviously, that particular race just needs to be optimized by the dev team, which I'm sure will happen. But that poster is right, it will destroy your FPS. It's a mess. But again, 99.99% of your time will be elsewhere, so it's honestly irrelevant.