i've been in a rental car on and off for the past 3 weeks due to my car being stolen... and i've had to listen to the friggin' RADIO
You should really look into an FM transmitter. Two quick varieties would be the I-rock and a Canakit transmitter. I own both so the pros and cons go like this. The Irock! is simple and small with that however comes rather weak output and it eats batteries quickly. The Canakit (hacked) can be used with a dc plug to power both it and your empeg. Its much more powerful and it has a larger broadcast range than the four choices of the Irock. The downside is that its larger and requires some sort of homemade case. I'd post pictures but I don't have access to a digital cam.

One of the folks on the floor, who has seen me around before, asked if I had tried the XM demo they had and wasn't it the greatest thing in car audio. I could not help but laugh and tell him that it would be the first thing I would rip out of the car, and I the reason I was looking at the radio so closely was to see how I could do it...

2600 had an article on XM and its problems this quarter.