This is more of a long shot, but I gave my roommate my Monster FM Modulator with 3.5mm (headphone) connection to hook up her MP3 player to play through her car radio.

She complained after the first day that it didn't work well and was very "shallow" sounding and she had to turn the volume waaaay up compared to any other radio station. I initially brushed her off and said that is how they are, but then went to her car to check it out. the problem was that the 3.5mm plug was not making a solid connection inside her MP3 player (Ipod Touch). I pushed in in further than seemed possible and it clicked and was full, rich sound. I would consider trying a differently designed 3.5mm to RCAs adapter.

 

thanks for all of the response everybody. I'll dink around and test some of these options.