There is no guide for this game yet. But apparently it is EASY POINTS! 

Tractor Tipping - 75 points

Successfully complete all levels of Tractor Tipping

Palm Mile Speedway - 75 points

Win the race by finishing in 1st place

Lizzies Postcard Hunt - 100 points

Collect all available postcards in Postcard Hunt

Motor Speedway of the South - 50 points

Win the race by finishing in 1st place

Sheriffs Hot Pursuit - 50 points

Successfully complete all levels of Sheriffs Hot Pursuit

Rustbucket Race-O-Rama - 50 points

Win the race by finishing in 1st place

Sun Valley International Raceway - 75 points

Win the race by finishing in 1st place

Smasherville Motor Speedway - 75 points

Win the race by finishing in 1st place

Monster Truck Mayhem - 50 points

Win the race by finishing in 1st place

Radiator Springs GP - 50 points

Win the race by finishing in 1st place

Tailfin Pass GP - 50 points

Win the race by finishing in 1st place

Ornament Valley GP - 50 points

Win the race by finishing in 1st place

LA International Speedway - 100 points

Win the race by finishing in 1st place

Tailfin Pass - 75 points

Complete necessary activities to unlock Tailfin Pass

Ornament Valley - 75 points

Complete necessary activities to unlock Ornament Valley