Playroom Help

I am starting to plan Nicholas' playroom.  We only have a three bedroom house therefore we are starting to get run out of our living room with toys.  Michael and I were talking one day and decided to sell our extra bed on craigslist and make that room a playroom.  As we all know, Michael is a car enthusiast, so I am planning to decorate in cars (although from the looks of the pictures, maybe Rainforest would be best!).  It is painted the same chocolate brown as N's bedroom, so I'm going to accent in red, green, and blue cars and stripes.  I think these wall decals would be cute.

I also bought this CUTE beanbag at Target a few weeks ago with this theme in mind for a playroom.  Michael loved it when I got home and showed him.

Now, the question is, what about toy storage?  I have a tall bookshelf, so I'm thinking for now having my dad make us a toy box and use the bookshelf to store baskets of books, small toys, crayons, markers, etc.  The other problem is that I have used under the bed and the closet for seasonal storage (boxes of fall, spring, and summer decor).  I'm at a loss of what to do with those things.  Does anyone have a way to store things like that in their garage without having to put them in the attic.  (I have a terrible fear of heights and can absolutely NOT go up the attic ladder, as sad as that is)  Any other suggestions for boxes or toy storage?