Moin! Would like to install a new radio.. Current radio would have to be the RCD200 driving a Polo 9N(3?) from 2006 and I thought about the Sony dsx-a400bt.. have now seen with searches that you probably need some quadlock adapter..? also I have read something about an ignition logic.. is this absolutely necessary? in a tutorial this adapter is used link .. are however also again 39€ Freu me over any help