to sum up all you really need is a decent cover & a trickle charger plugged into a Timer switch so it kicks on for say 20 mins a day to throw some juice in the battery. and a breatheable cover to keep moisture out and dirt/dust spider droppings (pita) off of the car while stored. a box of baking soda cant hurt either.
Something to keep rodents out of nesting in the vehicle cant hurt either.
mothballs, hifrequency rodent chaser, ball python.
Nothing funnier than fireing up a car after winter storage and having a pound of sunflower seeds & walnuts fly out of the tail pipe. from a packrat (squirrel).