I've used ammo boxes, tool bags, carpenter bags, etc. If you can store the cables separately it keeps things better organized for use - the cables are often not part of the service, and it frees them up from using the tools.
My current tool bag is a large double zip pencil case the size of a shave kit. If I can't fix whatever electrical gremlin is going bonkers with that, or the 1/4 drive kit in it is too small, I have a major problem and need towing. Shoulda caught it in weekly checks and maintenance. The 1/4 drive kit will do most hose, fuel injection, battery, and general maintenance, along with a multitip screwdriver and battery terminal tools. A pair of small vice grips, spare fuzes, etc. and I've covered everything I had a problem with in the last five years. Starters, alternators, belts, water pumps, etc, need a home shop environment where I can use the "big" box and grab another car to get parts. At that point it's time to get off the shoulder and home - which the invention of the cell phone greatly helps.