If the dealer used antifreeze expect to need a lot of flushing to get rid of the tasteless taste. If they put it in the freshwater tank expect even more flushing caused by this needless shortcut. This Fall do it yourself. Only takes an hour while doing other storage chores and antifreeze is not needed, just get rid of all the water in the system.
This Spring you'll also want to sanitize the water system. Plenty of instructions here and everywhere on the web.
Tire pressure will be low. Lug nuts will be loose unless you've been personally torquing them periodically.
-- Chuck