All interesting ideas...reminds me of when I was upgrading the sound in my old cruisers, scrounging for stuff that works and ways to make them fit (supertweeters in the A/C ducts, amps under the dash). Using component speakers will give more installation options.

I can listen to my stereo with good sound quality while cruising at 85, top down. And when parked or cruising, it sounds great. I can't ask for more than that! But when I'm "showing off", I turn the stereo off and let the engine make the music.