Review on 21 Cubic Feet Car Roof Bag: Waterproof Military Quality Rooftop Cargo Carrier with Anti-Tear PVC, Storage Bag & Anti-Slip Mat - Fits All Vehicles with or without Rack by Tommy Penn

A roof rack or bag can really help on medium to long holiday trips by freeing up space in the trunk or rear of the SUV for more important and easily accessible items. Great for blankets, pillows, tents, air mattresses etc. It takes some work to tie these tight and at high speeds the wind will move them a bit and possibly lift the mat in front and when we heard a few popping noises we left outside Make sure nothing was loose, and it wasn't (there was extra strap material that we should have wrapped better). It hasn't been used in the rain so I can't comment on the water resistance. Make sure the brand label is on the back. I would also like these items to come with reinforced sides to make loading easier, but that wouldn't allow them to be folded up to fit in the pouch provided (which fits nicely btw). The mat sticks to the roof and stays in place when you move the bag in place. Be prepared that lifting heavy things onto the roof will be quite a hassle and you will likely need a chair or stool to pack your bag firmly. We don't have a roof rack, but the door frame mounts worked great. Basically we are very satisfied.