I did this by playing the first season and using all my winnings to buy clothes that boost your stats, they can only boosted by a maximum of +2 each stat to a maximum of 12 so don't waste money buying two items that will give you plus 2 on driving for instance.
By the second season with all your stats up somewhere near 10 you should be able to compete fairly well, then save up your money for a max stas costume and then you can breeze through the Fedex Cup - I won it by 14 stokes in 2 rounds!