If you like Pandora on your iphone you can play it on your phone. I got one of these. its completely wireless with no cords.. just zip tie it to a rail or something and your good.. much easier than installing a cd player.
Amazon.com: Pyle Sound Flow PWPBT60 Rugged and Waterproof Wireless Marine Grade Bluetooth Speaker: MP3 Players & Accessories
Amazon.com: Pyle Sound Flow PWPBT60 Rugged and Waterproof Wireless Marine Grade Bluetooth Speaker: MP3 Players & Accessories