If you do an online search for indoor RV and boat storage in and around Corona, Calif., you'll get lots of results. Even if you put the restricting quotation marks around "RV indoor storage," the results will come back with every storage facility in or near Corona, and most of them will just be offering units for household goods.
When you get right down to it, there are only a handful of facilities in or near Corona that offer true indoor storage, but only a couple of them off any service for your vehicle during its storage.
McBride's, Power Sports, and Premier offer the most in terms of service, though McBride's is not even in Corona, but over in Chino.
If distance, or nearness, is important to you, then Power Sports and Premier are the only two left standing in terms of full- or near-full indoor storage and service. Power Sports' main service is to give it a pressure rinse upon arrival. If you want anything else done, the facility will recommend someone you can cal in on your own at an additional price.
Included in Premier's basic plan are these nine service promises, accomplished by in-house maintenance personnel and mechanics:
If you desire additional services, such as repairing fiberglass dings, you can get that too, but it will cost you extra.