just a little addition to the boot of my car, no need to write a guide, they're velcro! these may not be to everyones taste but I had never heard/seen them before and thought others may not have also.
I added these for 2 reasons, personal to me;
i) peace of mind (oil)
ii) keep things tidy.
I was always topping up the oil in my golf and through habit I always carry a litre with me (plus am doing 130 miles a day around the M25).
In the second I just put a multi tool, t-shirt and deodorant, and a rain poncho (heaven forbid break down)
the BMW ones are about £5 each but i got the Castrol one with a litre of BMW 0W30 oil for £12 bargain!