I purge my suburban at the trail-head and hide under the seats or cover up anything that doesn't look like part of the car. Things like empty water bottles, the clothes we will change into when we get back form the trek, and any spare gear. Normally we have our packs packed before we leave home and don't have any surplus groceries to worry about while we're gone. I do hide some water under the seats for washing up at the end of the trip except at the Hetch Hetchy trail-head.
Since you probably cook in the RV I don't think that putting your stuff in a food locker would make a bear think there is nothing of interest inside the RV. However if you did store the bulk of your stuff in a locker and a bear did break in you could tell your insurance company that you had followed all the NPS rules relative to food storage and thus could not have your claim for repairs denied due to a violation of the law. You would have clean hands.
Eeek could probably give some stats on bears breaking into RVs.
Old Dude
