I keep my all my vehicle fluids in their original containers and right inside the left rear door of my van in the side cabinet you see below to left of the fridge.
It has a removable top and is always easy to open and grab fluids when needed. Which is really not too often, other than the Red Line fuel additive I get a new bottle of every dozen or so tankfuls. Then I keep that 12oz bottle in my front door pocket. Come to think of it, I usually have a quart of oil and sometimes a bottle of steering fluid in the front door pocket, too, though mostly out of years of habit. This van doesn't need oil often and rarely needs brake or steering fluid.
Over the years I've found there's no sense--at least for me--in trying to decant fluids into other containers to save space, or to keep it all in some more out of the way place, as then it's a pain to get to when you want. I've got more room than a lot of you, though. I want it quick and easy when I need it and a easy spot to put it all back away after changing oil, etc.
I keep shop rags, oil wrench, funnels, odd bits of hose and hose clamps, hand cleaner, and any other typical on the road maintenance stuff in there, too. These side cabinets have been the best thing I ever did for storing stuff I don't need in daily camping, though I'll be changing that up soon on the left side to accommodate the fridge and a commode more efficiently. Tools are another matter. . . I have too many and keep them in the forward end of the other side cabinet so I can get them from the side door.
I'll get a pic of the inside of that side cabinet if you think it'd be helpful.
