There's really not all that much to clean as the fins are covered fairly well by the cover. If you store under a tree, I could see the need for basic cleaning of organic debris from the A/C tray. What's this smell you speak of?
2012 F350 KR CC DRW w/ some stuff
Cindy and Tom, Toby and Kasey (our Berner and Newfie)
Oh...I forgot the five kids.