Posters are nice, but BillBoards make a statement!
As a Chevy Dealer can you order BillBoards? When I was in the business, in my marketing kits were forms to order actual outdoor billboards. Typically, they ship directly to your outdoor advertising company, but I found I could have them shipped directly to the dealership. I had them wallpapered in many of the showrooms, and obviously added to my vast personal collection (I'd been collecting Corvette BillBoards since 1975).
I've since lost all my sources, but it would be great to have a new Vette or SSR BillBoard to add to the collection.
I'd definitely like an SSR BillBoard! They typically come in several numbered sheets and install with ordinary wallpaper paste. Just don't get the face too wet, it's paper. I had a buddy that use to install them for an outdoor advertising firm in New England, and they'd coat them for outdoor use.