That spot is taken up by my sleeping bag and bedding in my Rover 2000 automatic. I have had drive plate problems in the past so I carry a spare driveplate, as well as various tools. So if I cant fix her up straight away I have bedding to camp somewhere until I get her back on the road! At one winery I worked at I had to fix up a wine pump. I needed a couple of specific screwdrivers, which I had, so rather than trying to find the ones in the winery tool box, I went and pulled out the tools from the back of my Rover, and got the job done. The boss asked me where the tools came from, and I told him that I carried a full array of tools and spare parts in the back of my car to be prepared for any eventuallity!
I was asked the other day if the Rover leaked oil. My reply was, of course it leaks oil, it is a British car, and a leak and replace lubrication system is a standard feature, that way the oil will always be fresh!