I've been having a play on career mode over the last few days; its very enjoyable. However, what i cant figure out is the AI strength. It seems to be different for every track and in every car. For example, on N2 class, around the Nurburgring, i had to drop it to 88% to even be within a second a lap of the leading M3's in the Z4, but then in the M3 E30 i could easily compete with the leading cars and then when using the new M3 i found myself 4 seconds a lap faster than the other M3's in the race. In other words, the same white BMW M3's ran at the front of the race, but had vastly different speeds in each race despite not changing the AI strength. Is there a magic setting? What setting is everyone else using?