I'm not certain how it is done, but I have seen pictures of interstates with the trunk removed, with dual (std/tourer type) seats, passenger backrests (sissy bar), and luggage racks behind the passenger backrest.
As opposed to notching interstate fender struts for a trunk quick release setup (supervalk conversion), I think if you replace the interstate fender struts with std/tourer fender struts, then everything made to mount to std/tourer fender struts will bolt right up. But if you want to put the trunk back on, then you have to go back to the interstate fender struts.
Aside from the supervalk conversion, I don't know why folks would swap out the trunk with nice back seat and trunkrest for a sissybar backseat, except some backseaters may like/need the additional room provided with the sissy setup over the trunk setup.
One of my interstates has cobra std/tourer fender struts, no way to mount a trunk, no trunk to mount, and I am prohibited from calling it a supervalk.
