My MK3 Toledo Reference Edition has a Radio/CD unit with no aux input. I've been using an FM transmitter to play mp3s but I find the sound quality unsatisfactory. Does anyone know if it is possible to retro-fit an aux lead/input into this unit. I'd be happy to sacrifice the CD unit if the audio wiring for that can be utilized. Failing this, does anyone know if there is an upgrade unit to fit this car with either an Aux input or the facility to play MP3s from a USB drive?