Post-facelift (06/00) - as you say, no problem had I removed the other HU, but as I'd bought a JVC MP3 player less than a week before the empeg firesale, there was no way I could afford/justify an amp as well for a significant period of time (not yet, maybe soon).
So I had to have the empeg feeding into the JVC auxiliary in, which meant two players into the double-din slot, and with all the wires coming out of the empeg, and all the wires coming out of the JVC (it had a fairly chunky bundle too), plus wanting to keep the ISO connector so I could replace the stock unit when I sell the car, the space was very,
very cramped.
To the degree that needed to extend things like the wire with the fuse block on, because there wasn't room for that for quite some distance.
A.