I took my first long holiday journey to mountains with Rooftop Car Carrier Bag, carrying my two large suitcases within it on my Car's roof. Initially, I was afraid and drove at slow speed. However, after some time, I gained confidence and accelerated my car to 100 and 120 kms/ hour speed on highways. We encountered heavy rains during the journey. The bag kept our suitcases completely safe from rains and dirt. The bag was found highly useful. Please note that I used anti-skip roof-top mat also (purchased separately) beneath this bag to hold this bag in place and to avoid damage to my car's roof top paint getting scratched due to movement of bag at high-speeds. Also, don't forget to tighten the bag's belts to your car's side-rails properly, Also check the tightness of the belts whenever you halt during the journey and re-tighten them if necessary. If the belts become loose, your bag can be damaged due to movement of the luggage during the drive.