G'day,
I use a canvas tool bag I proudly bought from a "canvas bloke" at a camping show about 15-18 years ago. Wouldn't be without it. I bought it because the metal one I had was too noisy in the back of my station wagon, so I thought it might do the trick. It passed with flying colours, no rattles and didn't slide around scratching or belting into anything. It's about 14" long, and they do hold a heap of gear.