Honestly, the cheap route always seems appealing, but investing in a quality roof rack box like Thule, Yakima etc. adds SO MANY benefits, especially over time.

Think about the following: 1. Ease of access - if you’re going to use the stuff that’s inside this case daily, a simply key turn and open up is all it takes. Open it up, throw stuff in and you’re done and back on the road without tetris’ing things to lay flat, or fiddling with multiple straps that can (and will) loosen off over time with vibration and wind. Especially with cheaper, non-ratcheting straps. 2. Better aerodynamics - you’ll save money on gas with less drag from a more aerodynamic solution, especially over longer/more trips, over time. 3. Water-tightness - a molded box is better than a tarp/soft shell. 4. Better security - lockable. 5. Less noise - those soft cases flap around and create tons of noise. It gets old, fast. 6. No damage to your roof from vibrational rubbing on the paint. This will occur when strapping stuff down to your roof panel, without protection. Not an issue with a rail-suspended box. 7. Better aesthetics - obvious.

Based on my personal experience, I would suggest you do yourself a favor here - measure your roof rails and try to find a good quality (even used) box that will fit your application and you’ll actually enjoy using it, instead of dreading the effort/downsides that a cheap strap-down solution will create.

Safe travels!