Pro level race car class difficulty? (R1 R2 class)

I have gold in everything up to this point, all gold in the factory spec races on medium AI. Gold in all the other pro races prior to the race car classes.

But now in the R2 level races, the difficulty is incredible. The AI can close enormous gaps in a fraction of a lap, gaps I could never close. One small error and it’s game over, and the AI is forcing errors. Even in an unrealistic fashion. Even not braking to ram you off the road, ruining it’s own race and handing the lead to an opponent.

The gamefaqs guide doesnt even mention Race car class. I have tuned my car to the max.

I am just wondering if it is known to be incredibly difficult. Do you have to get all gold or just a podium finish?
Some of those factory spec races were pretty intense, yet rewarding. This, I am not sure about this. Just seems well beyond the rest of the game.