Basics
Step1
Drive slowly! Driving faster will not kill more zombies, but it will let you crash into more propane tanks, which will dramatically reduce the life of your vehicle!
Step2
Memorize the spawn points of the vehicles. There is a truck and a white car in the tunnels. Both of them are useful and both of them will save your life! The truck is at the far northwestern corner; the white car is at the far eastern end.
Step3
Use the shopping carts if your vehicle breaks down part way between replacements. Shopping carts allow you to plow through zombies quickly, allowing quick transportation while retaining zombie killing ability.
Step4
Kill the Convicts if you can! Their Jeep is, by a long shot, the strongest vehicle in the game. It may be slow, but there’s nothing tougher. Not to mention, the Jeep has a Heavy Machine Gun on the back! Make sure to grab the truck first, otherwise you’ll have to drop the Heavy Machine Gun to get into the Jeep.
Step5
Camp the area around the Maintenance Supply Room. Huge hordes of zombies spawn in the tunnels around it, and they respawn quickly. This is where you’ll probably be doing most of your driving.
Vehicle Specifics
Step1
Use the motorcycle only when there is nothing left. Running unpowered through the Maintenance Tunnels is virtual suicide. There are far too many zombies to fight by hand and come out reasonably intact. The motorcycle is only moderately more effective. It breaks quickly, can throw you off if you hit something, and is really only useful if you’ve got nothing else.
Step2
Use the red car to get from vehicle to vehicle. Like the motorcycle, the red car looks pretty, goes really fast and breaks much too soon to be of any real use when killing hordes of zombies. Only use it when you have to.
Step3
Use the white car for most of your zombie killing. It only has moderate speed, but so what? It lasts a good deal longer than the sporty red car and the motorcycle, which makes it ideal. It is also quite close to the Maintenance Supply Room!
Step4
Use the truck for some serious destruction! The truck is quite slow, but extremely durable! It can plow down legions before it dies, so use it to get you to an exit when its time for a vehicle respawn.
Step5
Have fun with the Convict’s Jeep! As stated, nothing lasts longer than this baby, provided you can get the Convicts off it. Bring it down to the tunnels and plow away!