You can earn money by leveling up and connecting to Facebook. Save it and purchase decals. A good premium decal can add thousands of silver coins to your race winnings. Participate in regulation races. Although they do not have large rewards, they can be won easily. Take part in the daily challenges, which feature three races with a loaner car. Get the two striped decal first, then wait until level 5 and spend no premium currency. At level 5, purchase the first premium decal for 40 stars to get a bonus of 1,400 coins for each race that you win.