I wanted a good way to store the tools I would need to fix what I can on the beetle. My 66 has had the back seat removed, so I could throw a big box in the way back, but I found this cool Toyo ST-350 (ST-350MG to be exact for military green) on Amazon and it works great. I can store all the tools I can need in here and secure it to the back seat/battery cover using a 4′ NRS boat strap.
I carry some wrenches and a voltmeter in an Adventure Tool Company tool roll, then screwdrivers, pliers, nips, needle nose adjustable wrench, 3/8 ratchet w/sockets and a Chapman MFG assortment in here.
I am sure there are 1000 ways to carry tools, but this works for me and my set of skills. Also that speaker is a Demerbox I use to listen to music.
The toolbox is on sale for $75 on amazon right now: https://www.amazon.com/dp/B09Z7XMSFX I got the 4′ skinny tie down from the local outdoor store.