My tool bag lives under the rear seat now as those bins are oddly shaped. In those bins, I keep ratchet straps, bungee cords, jumper cables and similar items.
That's where my tool bag is right now. But I suspect that space below the back seat is going to be prime territory for all my sweetie's swag (jacket, sweeter, umbrella, feminine stuff, etc.).
The only real reason I need this tool bag is because this will be the vehicle we use when we are together. And there's always the chance we will end up in a situation where I need a bag of tools. It all started after we found a metal patio rocking chair on sale at Ollie's in Hot Springs, Arkansas. But we were in the Charger Scat Pack. So I had to buy some tool to dissemble it and try to get all the pieces in the trunk of the Scat Pack. It took about an hour because I didn't have the right stuff. I was loosening torx bolts with a cheap pair of pliers.
But with the tool bag in the spare wheel well, I was recently able to scavenge a starter and updraft carburetor off of a junked antique Wisconsin engine we came across. That stuff is hard to come by but fits my geotechnical/environmental core drilling machine.