Vehicle Tower Defense 3

The enemies are attacking and everything seems to be in chaos.  Place some defense around the perimeter so the enemies won't reach your base.  Since the enemies are using some vehicles to attack the base, you are also using some vehicles to defend your base.   Place the tower vehicles in places where it can hit a lot of enemy vehicles.  Each enemy vehicle that you destroy means money on your pocket. Try to save as much money as possible to be able to afford the upgrades and some new towers.  The game become harder and harder as you progress in the game so you need to toughen your defense earlier in the game.