I just hope Volvo isn't to snobby to have one of those things. I'm nervous about asking for one at the dealership

Don't worry about that. It can never hurt to ask. Now, my Honda dealership was unhelpful in finding that part and I had to resort to ordering it online. But because they were snobby, because they had tunnel vision regarding the year/model of my car.

They would only start the part-lookup process by beginning at the top of the tree with my "2000 Accord SE 4dr" model as the starting point. And the problem is that the 2000 SE comes with a stereo for all models, so that cover is not available for mine.

Instead, I had to get advice on this BBS about an older model Honda (a Civic, even, I believe) that came with one of those covers, and then begin my own parts search starting with that one as a base.