We had one on our 04 Accord, used it on a cross country trip, all types of roads and conditions. It had to be removed and cleaned underneath the bra and especially the edges of the bra regularly to prevent abrasion to the paint from sand and grit. Finally gave up on it. Less paint damage without than using it.
In 6 years towing the CRV, never used a bra and the only stone chips in the paint happened when driving on its own, not used as a toad.
Ken