We used this bag on two long distance trips one from Minnesota to Montana (hello Yellowstone!) and one from Minnesota to South Dakota (hello Custer!) each at different times of the year and through different weather and it worked fantastic! We attached it each time to our roof rack and used the clips on the inside of the doors and it worked like a charm. We would go about 70-75 mph on the highway and had no problems with the bag and no speeding tickets either, ha! It didn’t seem to affect our MPG either.
We made sure to seal everything that we didn’t want to get wet in plastic bags because we weren’t sure if things would stay dry and I’m glad we did that. I suggest doing that. There was a little rain each trip and it is not a waterproof bag, but it did a good job at keeping most of the rain out. Things would’ve been a little damp. Especially if you are going camping with sleeping bags/tents/etc. that you have up there. It fits a ton of stuff in it and pretty much was a lifesaver each trip even though we had large vehicles, we needed that extra space. Nice bag and we will use it for years to come!
Here’s a link so you can check it out yourself: