Essentially the same thing I just replied to here:
http://igpmanager.com/play/?url=forum-thread_1/853#5045
There won't be any easy way to change this until the Q1 patch, where the option to reset your team will be added. That would provide a path back to Rookie for everyone without "corrupting" performance data. It will get even easier to race vs friends when we have the friendly race system a few months down the line.