Mr.SlowRight on!
When i did it I got between 140 and 150 per race. I guess it depends on the lineup. The hardest one was Infineon against the MX5 and the MR2 at the same time.
I won by 0.016!
My most difficult was Motegi as the Speedsters are a little to evil as they always get 6 seconds ahead if they get the chance.
Those races are easy to win as long as the Speedster is 3rd or below on the grid