!!!TIPS FOR THE BOSS!!!
Stay under him, dodge his fire. When he starts spraying bullets, remain under him for protection. When he stops spraying he stomps the ground. That is the time for you to go next to him and shoot him while he's on the ground and while he's taking off. Repeat until he's dead. I finished with full health and 50 sec left, so no problem.
PRO TIP: shoot at the boss until he dies.
I am adding a bit to what shottas said:
"To get the hard badge you have to be able to fly over the boxes. 1st day buy max transmission, engine, wheels, and spend the rest on fuel. 2nd day buy gun and as much ammo as you can. 3rd day buy boost and as much boost fuel as you can - use the boost on the very last hill to fly over the boxes and get the hard badge! ++ because it works! REPOST IF IT DOSEN'T GET VOTED UP"
1. There will be some money left on after you buy the gun or the boost - use it to max your fuel.
2. Tilt the car, so that it drives on its back wheels to effectively annihilate zombies - it's faster, saves fuel and you save bullets (the gun doesn't shoot when pointing up to the sky).
It worked for me perfectly.
 "Johnny Upgrade"){kind=icon}
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