[get me on the road]

Has anybody used those direct connect kits that hook your satelite radio to you after market radio. My radio has the aux port on the front of the radio, but with volume all the way up it still isnt as loud as a cd, and the same thing with the satelite radios built in fm thingamajig. I just want to know what the volume was like with a direct connect kit before I bought it. Also, if someone knows of a kit that will hook the satelite radio and an mp3 player to the radio, please let me know. Thanks in advance for any suggestions.