Hi I have the Audi A4 (B5) 1998 model which has the concert radio. Is there anything i can buy to convert this into Bluetooth so i can connect my phone via handsfree via the radio? I use to have the radio connected via a nokia phone, but this was removed when these phones became outdated! I now have an iPhone 4 and would like somehow to connect this via the concert radio. Any ideas good people?