Tokyo. Best tracks in the game. The Suzuki Carry daily race there about 6 months ago was the best daily ever imo.
Anyway, just one thing, not clear from your post whether you realise: The Sophy is always the same level (so practice can't really be on the hardest level), it's the three cars you drive that adjust the difficulty. One's strong, one's mid (one chilli) and one's weak (two chillis). The AI, as far as can be seen, remains consistent. You probably do realise this, just pointing it out cos the way it's worded in your post leaves it ambiguous.
And when you get to it, the Suzuka race in the Civics is sublime, but the hardest race in that whole 'Japan' strand on the top/right side. Hizal ultra aggressive in my many races there. Wondering if he was the P2 you mention putting you into the wall? Great stuff anyway.
Edit: if you can beat the Civic Suzuka race in the 2 chilli car without resorting to any dubious tactics, you're a much better driver than me, that's for sure.