So I completed install of my "low-fi" Aux Input to my CDR-23. I didn't want to replace the head unit, and the Dension unit seemed too pricey for my needs.
I bought a Scosche hard wired FM Modulator, and found the antenna adapters that fit the head unit (tip, the Car Audio places with tons of neon oustide actually have fairly knowledgeable folks working there, at least here in Chicago).
A few hours later, and a little trimming to the CD caddy, and I have a fairly polished Aux in transmitting on FM 88.3. Since it's a powered FM modulator sitting between the stock antenna and the HU, the signal quality is very good IMO - there is actually a station on that channel here, but when I switch it on, it is entirely killed, and all I hear is my iPod.
Sounds every bit at good to me as normal FM stations, just about 15% quieter...