I literally don't remember doing this test the first time.
I went back to it last night, and learned that it uses the Nissan Cube, a model able to barely achieve 100mph without drafting.
It took me three tries to win.
Try one I upshifted to fourth too early and didn't catch up to the others soon enough.
Try two I bumped someone near the end and lost my momentum, but may not have been making progress quite fast enough as I was leaving shifting until 105mph.
Try three I got it. Upshift to fourth at 103mph, downshift if you do get below that, but you shouldn't, IIRC, and carefully leapfrog the line to get to the front and win by over a second. I passed on the inside.
Actually, I think this test indicates the draft is not as high up on the banking as you might expect. I.e. you don't catch much from the "wake", but I actually don't know much about real-life drafting and am not sure how much draft one does get being behind another car but higher on the banking. After all, outside the drafting area should be an area of turbulent air, IIUC.