mm they FM modulator i saw from "ViewNet" comes with the line in features " works like a AUX " but then it uses Radiowave to transmit the signals or data. so the quality is not as good as the original AUX connection . but then it will definitely solve your problem.

all you need is the audio cable which connect your DELL Axim and the FM Modulator . that cable wont cost you more then RM 10 i guess. you can even DIY your self if you have does un wanted headsets

hope it helps for those expert out there please correct me if i am wrong hehehe

cheers