If you go off-road often, it's not a matter of if, but when you're going to need an air compressor, or some other source of compressed air. Whether it's for airing your tires back up before returning to pavement, or refilling a repaired tire, having a compressor with you is vital. Even if you don't plan on going off-road, it's still pretty handy being able to air up a tire now and then if you're out and about. I've also used my compressor to fill up water toys and sleeping pads.
I've been packing around a Viair 88P and assorted tire-related bits for a while now, but I've just had it all stashed in an old toolbag. That meant no real protection from stuff landing on it, and it was hard to pick out the right bag at a glance. I needed a better solution.
It turns out that Harbor Freight has some "Tactical Ammo/Utility Boxes" for a decent price and that the Viair is almost a perfect fit inside the box. I had to remove the tray insert from the box, as the compressor was too tall, but that wasn't a big deal.
I then cut a piece of scrap plywood to fit the interior of the box, and drove some screws through the feet of the compressor into the plywood. This helps to secure the pump so that it doesn't bounce around inside the box. To secure the pump some more, I used some metal straps I had from another project, and strapped the pump down. This assembly now drops down neatly into the box, and leaves plenty of room for the power cables and air hose. Once the hose and cables are in the box, they help to add some extra cushioning to the pump.
The lid of the box has some smaller compartments that are just the right size for some additional parts and tools. I've got a tire repair kit, with tools and plugs, and an old medicine bottle full of replacement valve stems, just in case I need one.
The box isn't waterproof, but it does have an o-ring around the lid that at least makes it a bit water-resistant, and helps to keep the dust out. Either way, it's still better than the canvas bag I had been using. And for $10, it's not too expensive either. Of course, with it being from Harbor Freight, there's almost always a coupon available, so you'll likely be able to pick one of these up even cheaper.