I store all that and more in my 2017 Lexor, between the batteries and the rear doors. Groups of related items are stored in small duffel bags. Each bag is tagged with the category of the stuff it contains (electrical stuff in one, tools in another, city water items in yet another, and so on). That way I don't have to unzip a bag to find out what's in it. I chose bags rather than hard-sided containers because each bag scrunches up nicely, saving room for its fellows.
It's a little bit of a challenge and takes some forethought, but you can put a surprising amount of stuff back there