The challenge is achievable with DS3, because I know I have managed to do it, and got a silver on Monza sometime after I got a bit of practise.
The trick to this challenge is trial and error, as well as alot of practise. I would suggest turning off the driving assists with the exception of SR and having ABS set to 1, since the assists kinda limits how fast the X1 can go around corners, and the X1 has so much downforce it doesnt really need the assists.