now from memory the antenna on the euro is mounted in the glass and has a powered booster for it to work. that booster gets powered by the head unit, the trick is to find it without doing damage to the head unit (or anything else for that matter) and find out if the trigger stays on while playing CD. if it does then that solves your amp trigger issue, if not then you will need to get an accessories wire to power the amp, dont use ignition to turn on your amp as you dont want the reds staying on while your car isnt running as you dont know how many other items turn on via ignition

in a nutshell hahahahaha