My Vaquero has a Mustang seat with a rider backrest and no backrest for a passenger. I have been looking at backrest options for my wife. Since much of my riding is solo, I like the idea of the quick release factory option. At the same time, when riding with my wife, we often do overnight trips and are always looking for more storage space. While discussing this with a friend, I was presented with an option to pick up a Tour Pack with speakers from a 2008 Harley at a very reasonable price. I would plan to mount it to the factory rear rack with the quick release connector. If I go this route, can I interface my factory stereo to the Harley speakers? Will this significantly complicate mounting and unmounting the trunk? Any other considerations I should keep in mind?