In order to get Full-surround Haptics you must ensure that the content you are playing is 7.1/5.1 surround content. Also, make sure that you are using a player that can play such content (e.g.: VLC, Windows Media Player). Some players need additional configuration to make them play surround sound.
Note: You must configure your Vest driver correctly to get the Full-surround haptic experience. Refer to this article for more information (Go to the paragraph: Setting Vest audio settings)
You can find Dolby 7.1 trailers in this link.