The door panel has a way of pressing and containing the VB - I just like the convenience of the heavier material and the ability to open quickly without tearing anything for maint. etc. I have done this for years and have never experienced swelling of door panels, excessive moisture, etc. True, door moisture could migrate through any gaps between velcro mounts but again, I think the door panel has a way of sealing the VB as well through light pressure. I think if window moldings, glass channels were badly worn, torn or non existent there could be a problem - I have owned more than a few cars that apparently had not had a functioning VB in years until I pulled the panel to discover there was no VB with no apparent damage to the panel - I orginally began this years ago with a BMW 2800 cs coupe with the usual window motor issues -