Yeah I can't do the Tokyo race worth crap. The road course was super easy, didn't make any adjusments and won by a couple of seconds. But Tokyo I just can't finish.
I've managed to beat this one (using DFGT, not the DS3). Key was figuring out to take an extreme outside line into Turn 1. You wanna be all the way to left, up against the wall, as you approach the braking point. The AI generally leaves a passing lane along the outside wall that can exploited with late braking. You also get a cleaner line to the apex and a chance to get on the throttle significantly earlier than the AI.
The inside line into the turn, by contrast, doesn't work -- it's slower, and leave you vulnerable to being hit and spun out. The advantage of the outside line on Turn 1 is so much greater that it's worth ignoring any inside-dive opportunities the AI offers there (even on the start).
Another key is having the guts to keep your foot down all the way down the ramp after you pass the subway station, until you have to brake for the left-hander diving under the bridge. It gets narrow but if you back off you lose too much time. The downforce from the F2007 is so strong you can still point the car accurately as you head down the chute. Lesser cars get squirrelly there, at least when I'm driving them.
Further issue, these races highlight how limited passing opportunities can be at F1 speeds. I could pick off opponents reliably at Turn 1 (thanks to the outside passing lane allowed by the AI), at the left-hander that ends the sweeper past the stadium, and at the right-hander leading back onto the home straight. Elsewhere, you're better off exercising patience.
The Indy race I haven't beat yet, but will likely do so once I try it again. Managed a 7th initially despite difficulties at the Turn 2 left-hander -- it's a place you can spin if you get on the throttle too early.
The Nurb GP, on the other hand, is a bear at these speeds. The Schumacher S is a real test of courage -- you can take it flat, but have to quick on the wheel to make the right-hander. I tend to lift slightly to make sure of staying on the pavement, and cuss myself every time I do.