"Further". All the way to the city dump.
Edit to say: I should know. When I was in high school, I worked at an early big-box discount store (in the pet department and lawn and garden), so I got a discount. I put a Sparkomatic AM-FM stereo 8-track, the crap they sold, in the '65 Cadillac, under dash, so as to not disturb the original in-dash unit. That sparkomatic sounded awful and last no time. I replaced it with a Craig unit that was some better.
I think I have a Clarion separates unit in the old Cadillac now, with separate tuner, amp and equalizer units, but have long-since lost interest in car audio and prefer the sound of the engine as the only thing to break the otherwise blissful silence on the road.