I actuall did the championship starting with a under-level driver (Level 22).
I won Fuji by pitting with from hards 9 to go, then making my driver drive like a madman on soft tires before everyone else pitted.
I won Nurburgring on a 3-Stop Strategey, running the race on mostly soft tires.
Monaco was a tough one, but my driver wrestled for and got the lead with 15 to go.
Monza was a tough one for me, as I though that a low-downforce setting would work like in real life, but after accidentally pitting on the first lap, I got up to third before I pitted for soft tires and won.
Suzuka and Indy had a similar strategy to Fuji: Start on Hards, end on Softs.