Turk, check out the Custom Autosound web site:
www.custom-autosound.com/ They make radios converted to fit into many old/classic cars . HOWEVER, they have a "Secret Audio" radio that allows you to place the unit in the trunk etc and control it by a wireless remote (on their web site Secret Audio is a pick on the left hand side of the home page) . You can get a hidden swing down / hinged 'face plate' as well that would tuck up under your dash out of sight when you want it out of sight. A fiberglass stubby boat antennae can be placed under the dash or in the trunk and several companies make 'swing down/hinged' speakers that could be stored under the dash and swung down when needed (used on many boats). The Hot Rod folks frequently use the Secret Audio radio set up in their rods . Good luck hearing anything over those side pipes but when in high gear and loping around or at stop lights etc you could at least have sound. I have seen other radios mounted in glove boxes and some actuall put it in the dash just like modern cars (duh). I have seen speakers everywhere imaginable . At least today you can get some decent quality speakers in small sizes. Enjoy the tunes. Bill