Outmax Car Rooftop Cargo Carrier Bag, 30 Cubic Feet Soft-Shell Luggage Bag Waterproof Car Roof, Include Reinforced Straps, Door Hooks, Anti-Slip Mat, Luggage Lock

Why I picked up the Outmax roof bag

I needed to reclaim cabin space on a long family road trip without committing to a bulky hard-shell box. The promise of a 30-cubic-foot soft carrier that could mount with or without a roof rack—and fold away in a closet afterward—was exactly what I was after. Over two weeks and roughly 1,200 miles of mixed interstate and mountain driving, the Outmax roof bag proved itself to be a practical, well-thought-out hauler with only a few quirks worth noting.

Setup and first impressions

Out of the carry case, the bag’s 900D PVC fabric feels thick and rubberized—closer to raft material than typical canvas. Welded seams and a broad zipper shield give it a purposeful, almost industrial vibe. The included kit is complete: door hooks for rackless mounting, plenty of reinforced straps, an anti-slip mat, and a basic combination lock.

Mounting is straightforward. With crossbars, it’s as simple as centering the anti-slip mat, setting the bag on top, and running the straps around your bars or side rails. Without a rack, the door hooks thread into the upper door frame; the straps then route into the cabin and back out to the exterior buckles. The whole process took me about 15 minutes solo the first time, and under 10 minutes thereafter.

Two setup tips made the difference for me:
- Use the full anti-slip mat under the bag. It prevents creeping at highway speeds and protects the paint.
- Route and cinch straps with the buckles sitting on or near the roof rails to avoid wind buzz and door-seal deformation.

Capacity and packing

At 59 × 43 × 20 inches, the Outmax is legitimately large. I packed:
- One 30-inch checked suitcase
- One 24-inch suitcase
- Two duffels
- A folded stroller
- A bag of camp chairs

There was still room for blankets and soft odds and ends. Because it’s soft-sided, it adapts to irregular loads, but it rewards smart packing. The best results came from building a flat base with the hard cases, then filling gaps with compressible items. The zipper opens wide enough that you’re not wrestling to get the last duffel in.

One thing to watch: on shorter or narrower roofs, the bag’s footprint can approach the windshield line or hatch seam. Measure your roof length before buying and ensure rear hatch clearance.

On-road performance

Road manners were solid. Properly tightened, the bag didn’t sway, and the anti-slip mat did its job. Wind noise was modest—less than a roof basket with an exposed load, more than a low-profile box. On my SUV, the added drag cost about 1–2 mpg at freeway speeds. That’s expected with any rooftop cargo, and the softer profile likely helps versus taller rigid alternatives.

I checked the straps at my first fuel stop and again at lunchtime; after that, they held tension. If you’re mounting without a rack using door hooks, you’ll want to snug them a touch tighter since there’s more give in the system.

Weather resistance

Soft cargo bags live or die by their water management. The Outmax uses heavy PVC fabric and a water-resistant zipper tucked behind a generous fabric cover. In steady rain and a short but intense downpour, everything inside stayed dry. I oriented the zipper toward the rear, fully closed the cover, and made sure the cover’s edges were lying flat—small steps that help a lot.

Because the zipper is water-resistant rather than truly waterproof, I’d still treat this as a “storm-ready” design rather than “submersible.” For long days in sustained heavy rain, I’d use packing cubes or dry bags for extra insurance, especially near the zipper line.

Security and the included lock

The bag comes with a simple combination lock that loops through the zipper pulls. It’s enough to deter casual snooping at a rest stop, but this is still a soft bag. If you’re leaving gear unattended overnight in a public area, consider moving high-value items inside. For most travel scenarios, the lock plus out-of-sight parking worked fine for me.

Build quality and durability

Stitching at stress points is reinforced, and the welded seams inspire confidence. After miles of UV exposure, a windy mountain pass, and rooftop grit, the fabric shows minimal scuffing and no cracking. The zipper pulls are chunky and easy to grab with gloves. I did notice a faint PVC odor when new; it dissipated after a day in the open air.

The buckles and strap webbing are robust and didn’t slip under tension. I especially appreciated the extra strap length, which gives you mounting flexibility. Just be sure to tuck the tails to prevent flapping.

Compatibility and mounting options

The Outmax is compatible with most SUVs and vans and works with crossbars, side rails, or no rack at all. With rails, the install is cleaner and quieter. Using door hooks is fully viable but comes with two caveats:
- If you pinch the weatherseal with a strap, you can introduce wind noise or, in heavy rain, minor seepage at the door edge. Double-check strap routing and close the door gently to verify a tight seal.
- Some vehicles with frameless windows or very tight upper seals are poor candidates for hook mounting. In that case, use a rack or aftermarket crossbars.

Maintenance and storage

One of the strongest arguments for a soft bag is how little space it consumes off the car. The Outmax folds down to the size of a small duffel and goes back into its carry case without a fight. After rainy trips, I wiped it dry, left it open overnight, then stored it. Avoid packing it damp to prevent odor or mildew.

Cleaning is easy: hose off dust and road grime, and use a mild soap on bug splatter. The anti-slip mat will trap grit—shake it out before placing it on the roof to keep sand from abrading your paint.

Quirks and limitations

• Zipper access at full height can be awkward on tall vehicles; a small step stool helps.
• The large footprint can overhang slimmer roofs; measure beforehand.
• The included lock is basic—adequate for stops, not a theft-proof solution.
• Like all rooftop cargo, you’ll feel it in fuel economy at freeway speeds.
• Soft bags are inherently more vulnerable than rigid shells in a car wash or to sharp objects. Use common sense when loading.

None of these are deal-breakers, but they’re good to keep in mind so you’re not surprised on day one.

Practical tips for best results

• Pack heavy items low and centered; lighter, compressible items on top and toward the sides.
• Run the zipper to the rear and fully cover it with the fabric flap.
• Cinch straps firmly, then tuck or tie off loose ends to avoid flapping.
• Observe your vehicle’s roof load limit (bag + cargo + rack).
• Recheck straps after the first 30–50 miles; they tend to settle once.
• If mounting without a rack, verify door seals remain tight and adjust as needed.

Value and alternatives

Hard-shell boxes offer better aerodynamics, lockable rigidity, and quick access, but they cost more, take up garage space, and can be awkward to store. The Outmax roof bag trades a little convenience and security for huge capacity, low cost of entry, and easy storage. If you take a few trips a year and want maximum flexibility, this is a compelling balance.

Recommendation

I recommend the Outmax roof bag for travelers who need serious cargo space without committing to a permanent rooftop box. It’s durable, weather-ready, easy to mount on a variety of vehicles, and folds away when you’re done. Pack thoughtfully, respect your roof’s load limit, and use the included anti-slip mat, and you’ll have a quiet, secure, and surprisingly roomy solution for road trips, camping, and family travel. If you regularly leave gear on the roof in urban areas or want faster, one-handed access, a hard-shell box may be a better fit. For everyone else, this soft carrier is a smart, reliable way to reclaim your cabin and hit the road comfortably.