In my experience with my Carnival, you might want to consider comparing the Drive Auto Car Trunk Organizer against bins. The Drive Auto fits that deep well better, but you gotta secure those straps for safety! For the middle row, the High Road Stash n Dash Car Seat Organizer is safer than loose bags. Be careful about blocking floor vents tho... Honestly, the Drive Auto is the best choice cuz it fits that Carnival depth perfectly.

Ok so, I've been thinking about your Carnival setup for a few hours now. Having spent way too much time measuring that deep trunk well, I've realized most people get it wrong by buying flimsy bins that just slide around. You need something with a structural base to handle the Carnival's specific floor geometry and the G-forces of highway driving.

For your situation, here's what I recommend:

1. **For the Deep Trunk Well**: I'd go with the Rola 59001 M.O.V.E. Rigid Base Interior Organizer. Unlike some of the soft-sided options mentioned earlier, this one has a rigid, non-slip base. In my experience, it's basically the perfect fit for the Carnival's well because it won't collapse when it's only half-full. The dividers are also customizable, which is great for separating heavy tools from road trip snacks.

2. **Between the Captain’s Chairs**: You gotta be careful not to block the sliding rails on the floor—that's a common technical mistake! I've found that the Tuff Viking 3-Compartment Car Organizer with Lid is a total lifesaver. It’s narrow enough to sit between the seats without interfering with the mechanical tracks. Honestly, the lid is the best part—it keeps the kids' toys from flying out if you hit a bump and gives them a flat surface for their stuff.

Basically, the key is finding organizers with high, rigid walls so they don't fold up on you mid-trip. Anyway, hope that helps you maximize the space! gl!

Just sharing my experience: i went through this exact struggle last year with our Carnival and honestly... it was kind of a disaster. HUGE warning: avoid the cheap, flimsy mesh bins from big-box stores. I thought i was being smart with my budget, but that deep trunk well is basically a slide. Every time i hit the brakes, everything shifted and crashed, which is literally so distracting.

I was pretty disappointed because those "budget" organizers just ripped after two days of heavy use. Tbh, for the middle row, i tried a generic soft-sided cooler between the chairs to save cash, but it just tipped over constantly and spilled snacks everywhere. It really wasnt as good as expected... basically, just be careful with the ultra-cheap stuff because i ended up paying twice when they failed. hope that helps you avoid my mistakes! gl!!