Door speakers right off the flight deck of the Death Star.
Now we all use Jambox or the like Bluetooth to Pandora or SpotifyYa, 80s and 90s, it was all about stereos (since technology has improved since the 60s/70s obviously), and not so much about horsepower.
I did the same thing (1987) on my front plastic door panels on my '70 challenger, only because I knew I could buy used replacements everywhere.