In an apocalyptic world, only with a 4x4 vehicle you can take on the new breed which dominates the land: the zombies.
Kill as many zombies as you indicated to level up. You can do so by accessing the zone level change. Look for it to find the zombies and survivors with the map.
You can kill zombies with gun fitted to the vehicle or mowing.
You can also repair your vehicle and make up time in the workshops.
Have fun killing zombies!