I have just started using a Sony tape adapter for my S50 sirius sat. radio. It has MUCH better sound than my iRiver FM modulator did (50$). In the Phoenix area, I couldn't use the FM modulators anyway- no available channels.
I thought the wire hanging down would bug, but I have the S50 mounted to the right of the radio, and the wire runs straight across and behind it. I don't see excess. Just leave enough extra for the tape deck to eject -- it has done that automatically a few times when cold.
What kind of iPod do you have? I just got a 2G shuffle (the tiny one), and I've been dreaming up a tape-adapter-mounted shuffle -- have a metal tab that comes off of the tape & sticks out of the front of the radio, to clip the iPod on. Clean, no wires hanging -- would be cool. Pull it out and go when you leave the car; nothing for theives to see.
I live in the airwave crouded LA area. My FM transmitter works great, but I whent with one that allows me to trasmit on all Freq. The tape plug for the iPod cept on getting frayed
If you do go tape, please remember to get a power adapter so that it can maintain power (Trust me on that one)