I believe in using heavy oil and a heat gun on a truck shotgun. Give it a good fieldstrip deepclean and oil with a good scrubber/solvent like Outers or Hoppes and then lightly oil the internals and bore with Remoil or CLP. Then I'd heat the exterior of the gun extremely hot with a heat gun (use gloves or oven mitts obviously) and rub in some motor oil (don't go overboard with it and try to keep it out of the internals) while it's hot. Rub in until it's cool. Then when it's cool rub a very light coat of remoil in and store. As for storage, I agree with Hogdogs if it's short enough to go under the seat that's where it should go. Try to find a softcase that fits it close and snug if it's a fine gun, if it's a Mossberg, use nothing because Mossbergs only get prettier with abuse.
