You can also swap a used HU-650 unit, preferably one from the same year. Connecting a HU-650 should be the reverse of this video
https://www.youtube.com/watch?v=PGQJWxoc5aE - there should be another connector + a DIN one hidden there behind the unit that would plug into the HU-650. The HU-650 will not use the amplifier or the center speaker, but should sound fine otherwise. The HU-650 also has only 1 CD. The car battery must be disconnected during such swap.