Earn to Die: The Final Run
It will take the third car to reach the helicopter at the end of the game, this means that your priority is to earn up enough money to buy the upgraded car instead of maxing out the stats for your first two vehicles. Concentrate on gas, tires and transmission, and just buy the level 2 engine if you can afford it. Keep the rest of the money for boost or for saving up.
Eventually, you will earn enough to buy the next car in line. Keep doing the same with the van and you will be saving up enough for the trailer in no time.
The real fun begins once you have the trailer. No need on maxing out the gas immediately either, the default amount is already pretty sufficient (though you should max it out later on). Focus all your money on getting the best upgrades without having to buy the level two ones. The only exception here is the tire, since the tires can only be upgraded once with the trailer. Do not be mislead with the whole “super tire lost in the apocalypse”, so far no one has ever managed to unlock the piece, so we will consider it to be non-existent. Once the transmission, tires, and boosters are ready, you can expect to earn plenty of money per attempt –and maxing out the gas and engine becomes a matter of simply doing a couple more runs through the stage. Once you have everything maxed (you could even buy the gun if you have the extra money), it is time to get to the end.
Making it to the very end of the game now becomes a matter of managing you fuel so that all your accelerations are well placed. Boost here can be deployed for supplementing your uphill runs or, for better effect, to get your car launched upward into the sky. Forget the attacks from your gun since the zombies it takes out at the start of the run are negligible, though if you get lucky, you may have a few shots left by the time you reach the bigger zombies after the 1000 mark, which is a very useful thing to have by then. Lastly, try to focus on keeping both tires on the floor in order to maintain top speed and to avoid being tipped over. As long as you follow this simple tips from the beginning till the end, you will definitely make it to the goal.