Ok, here's what makes me happy driving with iPod driven music. In case you've been thinking about this one for a while.
I went with a Sony CDX-F7005X Xplod stereo. It has auxillary out in the back.
Ordered a Sony XA-300 off of Ebay from a guy in Canada so the price was great. (You need this for the auido line in.)
Belkin stereo adapter (cause it's what BestBuy had in stock, I guess you could go with a Monster)
Blank insert (where the 6 disc changer was)
Hole drilled in this for the line-in audio. It makes a great area to keep the iPod and a phone or what ever.
Only draw back i found was the car charger causes audio feedback, like a tape hissing sound.
But the audio sound quality is awesome. I was using the tape adapter and hated it, though it was the best out of 3 (tape, tunecast, and iTrip)
I've seen some cheaper alternatives. with the line-in in the front but i wated a cleaner look.