Drevs

Hello everyone I have been considering buying a roof bag for my 2017 Tekna with a panoramic roof. We camp and have lots of stuff (bedding, coats, etc that I want to put in it). I've come across one site (a roof box only - sales site) that says you can't use a roof bag with a panoramic roof. I don't have bars, just the standard roof rails to attach it to (and, of course, would use a non-slip mat). Has anyone had any experience with a roof bag and/or panoramic roofs? Thanks