Aftermarket Stereo question


Registered User
Hi guys,

Im trying to install a aftermarket stereo into my A3. Ive got bose and am keen to retain it so have got all the leads etc to hopefully make it work. I have also got aerial adaptor to allow me to listen to the radio and its a PC5-137. My question is once i have plugged in the little yellow plug and wired in the 12 supply to the lead what do i do with the other old style aerial adaptor as its got no were to go as this new lead plugs into its place?

Any help would be appreciated