I put my driver in a 650bhp Nissan Fairlady, the car tops out at 230mph at SSR-7, has good handling/traction and very good acceleration. He then went and lost the supercar challenge at high speed ring. I have no idea how he can drive such fast cars so slow.
I then put him in the horrible Murcielago Chrome, tuned to 720bhp (though slower than the Nissan), and he was able to win, and absolutely thrash everything at daytona, but at nurburgring it took him 2 tries (and i further tuned the car after the first loss), he only won at the last corner because the Mclaren F1 spun off. It seems B-spec Bob likes 4WD cars, and especially doesnt like tuned up japanese imports.