Aren't they identical from the axle back? I don't know what the tie-in looks like, but it seems like a small part of the kit, if it had to be modified at all.
I use two factory onboard bags.
They are good quality, but the center divider is a joke. It doesn't do a good job of preventing the panels from rubbing on each other. Much easier to insert, and zip, one panel in each bag.
Went through that at the TX/NM boarder a couple of years ago. Had to come to a complete stop. It was like the windows were wrapped in burnt orange construction paper. Then the muddy rain came.
I use this one because it runs on the same batteries as my power tools and landscaping tools. I also have plug-in tripod LED lights.
https://www.lowes.com/pd/Kobalt-24-volt-Max-700-Lumen-LED-Rechargeable-Power-Tool-Flashlight/1000812922