ok thanks for the info..., I've sorted my MP3s
I was searching around to see what devices would be able to step down/convert the 4V output, im wondering whether the following would be Ideal
http://marketplace.xtra.co.nz/cgi-bin/dse.storefront/1619340215/Product/View/A7303
OR
http://filemaker.webfactory.com.au/DFX/jaycar/FMPro?-db=products.fp3&-format=detail.htm&-lay=cgi&Category=CAR%20SOUND&-recid=32886&-token=12597204&-find=

cheers,
Jai