HI Bobster,
Unfortunately you cannot, there is no Aux in and the Bluetooth is for phone calls only :(
I am going to get one of these : Make sure you have the 8pin CD changer socket as I have a Concert II which is 12 pin...
https://www.amazon.co.uk/d/Electronics-Photo/Adaptor-Audi-Radios-Chorus-Concert-Symphony-Navigation/B00DZKPE5S/ref=pd_lpo_vtph_107_tr_t_3/259-1195127-9283300?_encoding=UTF8&psc=1&refRID=S1JVSSHM7364PV3H4CMJ
40 quid and should be plug and play, but you will need to plug the iPhone into the Aux socker, or just burn a 32gb SD card with all your fav music.
Alternatively https://www.amazon.co.uk/USB-Adaptor-Bluetooth-Audi-Radios/dp/B00DZKXGJY
This gives you Bluetooth too :) again you need the 12 pin if you have the newer Concert 2