Although there is lots of storage in our Big Sky 3575RL, I wanted more for bulky light weigh items like paper towels and snacks. Above the Microwave oven is a "Blank" panel hiding a very nice empty space. I got a wooden door from a RV Surplus store in Quartzsite Az that matches very close to the other cabinet doors. I knocked out the blank panel and installed a shelf inside. Mounted the new door and hardware! Handy, looks great and stores lots of stuff.
Check out my website for photos of this project under Improvements:
http://www.moneysmith.com/w4nfrweb.html