What you want to do is add an AuxIn from an external source to the head unit. Unforunatly, there is a logic signal that controls the disk #, track #, and FF/RW commands, so you cant just solder in some RCA connectors. What you need is a box by USA-SPEC called the PA11 that emulates this logic signal. It has an Ipod direct cable that lets you control any iPod with a dock connector through the head unit, and it has an AuxIn cable that lets you connect anything else, like another brand MP3 Player, or iPod shuffle. It is around $100 and connects one of two ways:
If you have a '01-'05 (except s40, which is '01-'04) You'll need the PA11-VOL that works with the HU head units (HU-450/650/850 etc), which is $107 here:
http://www.audiooutfitter.com/store/PA11VOL.html See detailed compatibility here:
http://www.discountcarstereo.com/detail.aspx?ID=726
Or if you have a '94 - '20 modle, youll need the PA11-HON that works with the SC head units (SC-710, SC-810, SC-811, SC-813, SC-816, SC-901 etc ), which is $107 here:
http://www.audiooutfitter.com/store/PA11HON.html
Ehk niisama lihtsalt seda teha ei saa, kuigi võid ju kasutada fm saatjat või ma hetkel ei leia üles selle raadio tehnilisi andmeid, aga kui tal on ka kassett, siis saad ka sealtkaudu signaali sisse ajada.