During war times, we need to be tough. Those, who are just there to experience it will be the first one to die as they can't last long in such a harsh condition. They don't have the will to survive long enough till the situation is better. This is the same thing with vehicles. If the vehicle is not meant for a war situation then it will be the easiest target for enemies. That is why, you need a monster truck during these times as it have the mobility and the toughness needed during rough times. You can also mount in some weapons for added protection and put some more plating for the truck, so it won't be easily destroyed.
Drive the truck to war. Make sure that you can get to the finish line before your life bar is down to zero. Grab some green boxes for added points. Those health kits will be handy when your truck's life is getting low. Fortunately, you can get it for free on the road. Shoot those barrels as it will explode upon contact with your truck. Try to get back on the road, should your truck flip on its back.