Not if you have already accomplished the "Hard" settings, which release additional tracks and cars for use in the Arcade mode. Professional is just for people who think they are awesome ... like you and I (:
Originally posted by secretghost007 also no percent bonus is gained for pro mode and from my experience when you do it before you completed hard you dont even get credit for any of them.
Really? That sucks ... I thought it would have at least given you credit for Hard. It would be really cool if it gave you Formula 1 cars in Arcade mode, or LM cars or something. Oh well ...