Tony, I had been using a cassette style that Brian spoke about. He's right about the FM Transmitter type, it's just OK and would work marginally at best. In RI since our airwaves aren't as jammed as they would be in NYC or other big cities the FM transmitter if you don't have a cassette player would get you by. I noticed an appreciable difference when I went from the FM Transmitter to the cassette option.
I like Don's idea about the Scion since you may not be in the market for a new vehicle here's another option.
Santa Claus brought me a Pioneer radio this past Christmas that not only has an 1/8 inch input jack, but also came with a free iPod adapter that works great. The radio was $129 on sale at Circuit City and the quality is above the stock factory radio.
Our buddy Frankieve is in the car stereo business you may want to contact him. What better way to spend the day having Frank's crew install a new stereo while you get to play all the new keyboards he has in stock.
[This message has been edited by Stephenm52 (edited 02-04-2009).]