Apart from F1 - Who are the top earners?

Of all the pilots driving in the world, statistics shows that the top earners are all coming from the F1 world. But needless to say that there are drivers that are earning huge sums of money that are doing their things in other motorsports series.The best paid non-F1 driver is Dale Earnhart Jr who earned, in 2007, more than 27 $ million which include a salary of 5 millions $ and commercial endorsements worth about 22 $ millions. Junior is closely followed by Jeff Gordon at 26 $ millions and 2007 champion Jimmie Johnson at 18, 6 $ millions.Apart from NASCAR, the highest paid driver in North America is now Danica Patrick with combined revenues estimated at 5 $ millions.