Car Luggage Carriers - can you rig up one of those cargo bags for the roof of your car to work with no roof rack?

can you rig up one of those cargo bags for the roof of your car to work with no roof rack?

We have a 2004 Honda Element Ex we do not have a roof rack on it.

if the thing has straps you can have someone inside pull those towards each other as the back doors are closed(somewhat holding the straps/bag in place) and keep a eye on them while riding in the back seat you need to put some cloth or something to keep the straps from rubbing away your paint but i think it will work just as long as the stitching doesn't go goodluck
Might dent your roof. Spread the weight out the best you can. Roof damage is just about the most expensive thing to fix. It is not like a fender that can be removed/replaced. Do some test pushes with your hand. See how well the roof holds up to 50 lbs of pressure. Roof racks move the weight out to the edges of the car where it is stronger. Anything from 2-3" from the edge of the doors have little to no bracing.