RV Lifestyle: Removing the Sprinter radio, repositioning the antenna

The Chevy was blessed with a fiberglass top, so you could just throw the antenna in the storage area over the front seats and get great reception. Sprinters have metal roofs so that's not an option, and radio installers usually place the antenna under the top cover of the dash, as far forward as possible, and try to get a signal through the windshield. Source