Plot hole: Even if boys of that age had the technical know-how to quickly repair Jeeps over 20 years old (seriously?), any gasoline in the tank would have long become unusable, the tires and lines would have rotted away, and the electrics would all be dead. Now if it was in the desert or a dry garage, it may have survived, but it's on a tropical island, in a shed that has all sorts of holes in the roof, leaving it exposed to every kind of weather the island could throw at it. In addition, the kids start the jeep with the small battery of an ATV, which cannot produce enough power to crank a Jeep engine.