Friend of mine has a hard drive installed in his truck - he basically took his cd collection and copied it. I want to do something similar but we are talking about over 25 Gb of music from around the world. I have the stock Bose system with the PAC running to a pr. of MTX subs. Is there an aux input or something in order to retain the factory HU which I am happy with (at least for now). What hardware manufacturers are out there that might be able to help? Thanks in advance.