Brought these magnetic tool holders. They have magnets on the bottom which hold it solidly to the bottom of your toolbox. You can also cut them down which is handy. I was actually surprised how much space that was made available by adding these in the drawer. Very happy with them.
The spanner set I use the most is in a roll bag, makes it easier to pick up and go where ever, im terrible at knowing which size I need and hate having to crawl out from under the car 3 times because I got the wrong size