Audi A4 Concert with only CD/SD button

[Kokicha]

Sorry, I know this post is months old now, but I’ve only just come across it. The basic concert radio does have an AUX port already built-in, its just that some models don’t have it wired. You can purchase a plug/cable on-line and wire it through to the centre console (or wherever) yourself. Obviously you’d need to remove the radio and a few other items to run the cable, but actually not too difficult and there are plenty of videos on-line that can guide you. To access the AUX as an input, there is a config change required that is done via VCDS. Also, there is a software update available to increase the capacity of the SD card reader from 4GB to 64Gb - you need a dealer to do this, but I’d suggest the AUX port is the way to go.
Looks like this info is too late for you but may benefit others.

[RobbieM]

Thanks Kokicha,

still considering options for this, have been using an FM Transmitter which is not ideal! (it seems to jump wavelengths randomly while in use which is a.annoying and b. scares the sh*t outta me!
I'll have a look for the aux port, any idea how you select this input for playback given there is no aux button on the headunit?

[Kokicha]

This thread should provide you with the answers you need re. Using and enabling the AUX port: 2007-2008 concert-symphony cd/sd aux-jack possible | Audi A5 Forum & Audi S5 Forum