We used this for our 1200-mile move from Texas to South Carolina, and it is a great find!!! Definitely listen to all the people who recommend a PVC frame. I'm so glad that we did this. It definitely helped keep things weight balanced, and the bag didn't budge from my car even when we hit bumps. I was a bit nervous about that and concerned about the bag falling off the car (after reading some previous reviews), but my mom was traveling in the vehicle following me, and she said it didn't budge at all and just moved with the car. I don't have a roof rack, but I bought the car clips from the same company (https://www.amazon.com/gp/product/B008YS3V88/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1), and they worked great. I also purchased a protective mat (https://www.amazon.com/gp/product/B07GDBGDWV/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1) to place between the bag and the car, and I didn't have any issues with scratches. I was a little confused about the instructions in terms of the bottom straps, and I'm still not sure I put them on completely right, but I think the main goal there was to keep the bag stable against the car and from bumping along, so it seemed to work. It could also be that the bag was weighted down enough that it really wasn't going to move. For the PVC frame, I had trouble measuring the pieces and could have gone slightly longer, but it still worked well. I didn't want to have to use a wooden bottom and sand the edges, so we cut out a cardboard piece to be the right size and then stabilized that by wrapping it in duct tape. It worked great for a stable floor. I didn't weigh the bag, but I think we may have exceeded the 100 pound recommendation. I'm not recommending you do that -- just saying. We also ended up putting the bag on the car first and then loading it, and that seemed much easier. I stuffed the bag to the brim with a few bags of vacuum sealed clothing (the medium and smaller bags -- not the extra large size.) We also had a couple of big ziploc totes with towels and bedding (something like this: https://www.amazon.com/Ziploc-70162-Flexible-Totes-Jumbo/dp/B003UEMD1M/ref=sr_1_2_s_it?s=hpc&ie=UTF8&qid=1539893571&sr=1-2&keywords=ziploc%2Btote.) We had other random bedding wrapped in moving wrap and at the last minute we added our robot vacuum and charging base. I had a small lock, so I used that to lock the two metal parts of the outside zipper together. I imagine someone could have broken into this if they really wanted to, but I have the feeling it would have been noisy and not quick. We spent 2 nights on the road staying in motels, and we didn't have a problem with security. Of course, we were in relatively small towns too for our overnight stays. We were in Florida a day and a half before Michael hit, and we drove through heavy rains throughout our trip. In the last hour of our drive, even with the wipers on the highest setting, I had to slow down and use my hazards because visibility was so poor. Despite this downpour, when we opened the bag, everything was dry, and I didn't find any water inside the bag. Again, I think the frame helped here because with the bag keeping its rectangular shape, the flap over the zipper was able to stay in place and keep water from going into the bag. When we unloaded the bag, we even had a pool of water on top that i had to scoop off. I was a little skeptical of putting my license in the bag as well, but you can only access the license from the inside, and it fits tightly in place -- especially if you pack things in place like we did. I suppose with a sharp enough blade, someone could cut through the outside to get to your plates, but it wouldn't be a quick job. In terms of gas mileage, it didn't seem to cause any reductions. I also checked the straps at every stop, but the only ones I ever had to adjust were the bottom ones (and again, that's likely because I didn't put them on right. I think if I could find some thin ratchet straps I might use those next time instead. I also like the idea of another ratchet strap underneath the bag -- maybe with a couple more of the clips. I don't know that it was really needed, but it would have been more for my peace of mind. Also, like others have posted, I didn't have an issue with using the bag while driving at high rates of speed. Yes, I drove through Texas with some high speeds, and I never had a problem. For the cost of this compared to other options -- including trailers and hitches or roof bags and racks -- it was definitely well worth the investment. I could easily see myself using this again. It's not the kind of thing I would set up and use for a quick trip -- but definitely for a longer one where I didn't need to get into my trunk and wanted to haul a lot of things. p.s. Amazon, can I get credit for a roadway referral? While stopped in traffic on the interstate in Louisiana, I spotted someone taking a picture of my cargo bag. He wanted to get the brand name to know what to get. He then pulled up next to me, and I told him he could purchase it on Amazon. p.p.s. If you're that Cajun gentleman from the interstate in Louisiana that saw this on the back of my white Kia Sorento, then yes, this is the bag you should get. If you want it to look as beautiful as mine did and be as stable, then definitely make yourself a PVC frame and something to use as a base/flooring -- either the wood people have suggested or cardboard wrapped in duct tape like I did. (For everyone else, sorry, there are no pictures. After our long trip and the longer time spent packing up and unpacking -- not just our two SUV's but a 26' moving trailer too, I just didn't have the time, patience, or energy to take pictures.)
