Sure.
Here is the program with a few more blank lines:
import java.io.* ;
class Car
{
  . . . .
}
class MilesPerGallon
{
  public static void main( String[] args ) 
  {
    Car car1 = new Car( 32456, 32810, 10.6 );
    System.out.println( "Miles per gallon of car 1 is " 
        + car1.calculateMPG() );
    Car car2 = new Car( _______, __________, _________ );
    System.out.println( "Miles per gallon of car 2 is " 
        + ____.calculateMPG() );
  }
}