Answer: Eight satellite lots will be needed to accomodate all the vehicles.
Expected turnout for the game 70,000 fans
Proportion of people expected to drive 60%
Number of people expected to arrive by car:

Number of people per vehicle 2
Expected number of cars
Number of car parks in the stadium 9000
Number of additional car parks required
Number of car parking per satellite lot 1500
Number of satellite lots required