RE: Lid over the engine battery
The lid over my engine battery has not been screwed down since I got the
van, I don't think it was at that time either.  It does a fine job of just
sitting there, held in place by the carpet flap.  And the flap doesn't have
anything holding it down.  It once had some double back tape there but that
gave up the ghost long ago.  And never any problems with any of it.