hi i have put the standard aerial back on my a3. 8L installed the standard head unit. plugged every thing as standard. im still not getting signal. when i search for radio stations it doesn't find any if i press the scan button it finds all different stations but i dont no weather there all pre installed ones ? if i want to search manually with the little arrow top right of head unit it will scan through the lot without picking up a station can anyone help with information on this please ? this is weird as well. when i had the shark fin on the roof it wasn't connected to anything. i put the standard head unit in and i could listen to the radio from the pre installed stations .