AUX connection for high performance system

Meal! My C30 has the AUX connection at the rear of the radio or in the compartment below/behind it. So far I was happy that I was able to play my CDs, because my music collection was almost only on CD. But now it has grown and I would not like to let it play via CD or MP3 player, but would like to connect my HTC Magic there, because this offers a close to inexhaustible range of memory and movies (which could be heard so well by the car speakers). So, now I’m looking for a useful connection already a few weeks/months, but find nothing to see from AUX (male plug) with a male mini USB port or a female USB connector to then be able to connect a “transition cable”. Do you know where I get something like that? At Volvo it always means: “No, we would only have the connection possibility of an IPOD adapter with USB and that is only possible from 2008″…