If you see an objective item (Gas can, Phone Fuse, Car Battery, Boat propeller or keys), pick it up and drop it. Even if you are not going to use it yourself. This will ensure everyone with access to a full map, or if they are close enough for the mini map, can see that there is an objective item there. Even if you are not running a repair character this will increase everyone's chances of survival as they will know where to go to get the item to finish up the objective's to escape.