The original factory radio has a preamp in/out in the back designed to connect to an equalizer (I have a 91 DX). Therefore it is possible to connect an external device, like an ipod or a cheap CD/MP3 player. This is a very cheap solution, although it isn't as convenient as a regular in-dash MP3 player. I paid 40$ for a Panasonic CD/MP3 player with a remote that fits well next to the parking break. Each CD holds hours of music, so changing CDs is not so frequent. with a small 50$ amp, 50$ sub, and 80$ speakers, the sound quality is excellent. The wiring took some work, and I also built my own power supply for the CD. I didn't intend to spend that much on the sound system, but after I installed the CD player, i was tempted to improve the sound. The original cassette player is not as bad as the horrible factory speakers, so I don't think there is a point in investing in a new unit without upgrading the speakers first.