@Antan, did you beat these challenges without skid recovery force on? Seems like many people are resorting to turning it on for these events (mostly on the Focus and RX-7 ones). I tried it on the Focus/Madrid race, and I beat it very easily (passed first before the last lap). Without it, I dunno if I could beat it... I was always a few seconds behind (but I was slowly making progress).
In the RX-7/Tsukuba one, after 3 tries, the best I did without skid recovery force was 10-11 seconds behind first! My lap times were mid ~1:01's. I'm gonna try it with it on tomorrow sometime.
The first and third races I beat without assists, and I have yet to attempt the NASCAR/Ring race.
Skidrecovery on but that's it. The general word on the street is that's they are impossible with skid recovery off. I got to second with it off, but 1st was always out of reach, no matter how hard i pushed. As everyone is saying, "it feels dirty". I NEVER use skid recovery but had no choice with these events.