I like your idea on the compartment lid being hinged at the cross support. How much will the mattress hinder opening the compartment lid on the rear section? I've been thinking of cutting in an access into that area to avoid lifting the mattress during camping but still get access to the storage area.
Thanks for the ideas!
2016 28BHBE Elite
2008 Chevrolet 2500 HD Duramax w/Allison
2010 GMC Acadia