why don't you use a wireless fm transmitter?
here's one I found, after googling "wireless fm transmitter"
Jensen also makes a transmitter, but I lost the link, sorry.
imo, this is an easy, inexpensive alternative.
btw, I have had no experience with the company whos website I gave you. I do not vouch for their service, I was merely showing you a viable solution to your problem.
Thinkgeek.com imo is a better company to deal with, but I cannot find their "Jensen wireless transmitter" which they sold last month for $39.
~Branson