Under dash 8 track
I put am 8-track player in my first ride. Radio Shack add-on fit nicely under the radio where the ashtray would go. I jammed to Meat Loaf's Bat Out Of Hell album many a time. That and Led Zeppelin II. We even had an 8-track recorder in house at one time and made our own tapes. I have seen them on Ebay too for sale. The only thing about 8-tracks was the fade out/fade in on track change. If you made your own and timed it right, you never had the song cut in half. Beat flipping a cassette all the time unless you had auto reverse. Would add a nice touch to a stock setup especially if it worked and you had a tape to play in it at cruises.