Improved shooting mechanic and environment

After a few testing sessions, I felt that something was wrong with the aiming of the projectile.  The projectile always seemed to shoot at a trajectory just behind where the mouse was pointing.  After taking a day off, the solution occurred to me.  The projectile was not in the car's frame of reference.  From the frame of reference of the camera moving forward at 50 m/s , the projectile seemed to be moving 50 m/s behind the correct trajectory.  This issue has been repaired.

Also, my co-student at UCI Amen Wondwosen just improved the track to make checkpoints visible to the player.  This way, player's will hopefully understand when and why they get a "pity boost".  Thanks, Amen!