Assuming your victim is small, you could remove your spare tire and store them in the spare tire well under the bed…no release included for that space. That is why you have the “dividers” included if you don’t buy the spare.
This is, of course, simply an academic discussion with no real basis in reality…just sayin’…
I would stick with the frunk because you can dynamat it for sound insulation. The power tonneau panels don’t really have room but you could probably inject some foam into them.
Also people are less likely to notice sounds coming from the front of a “truck” as you pass by. Just tell them it’s a bad idler pulley.