Buckle up. You're going for a ride. Race at speeds over 140 MPH on dirt, on the proving grounds for today's top professional drivers. Shoulder to shoulder sprint car racing makes for spectacular crashes, and white-knuckle driving.
Most popular community and official game content for the past week.  (?)
What does popular mean?
It means the content you're seeing has been rated up more than it has been rated down for the given time period.