wide open plains? you should check where Harley Davidson's "speaker driven" Electra Glide and Honda's Gold Wing or any other couch-with-motor-and-handlebar-and-speakers-motorcycle sold mostly within the last ... lets say 10 years.
those who ride with music don't care about the audience, in general.
some models offer speed-related volume. at least for the rider it sounds more acceptable when stopping at red light ;-)
