Duncan.c1992

Hey, this is my first post so go easy! I have just bought an 2005 Audi A3 and I wanted to install the radio from my old car (Golf) because it had Bluetooth, I saw various posts online about needing a PC9-401 adaptor to get it working so I went to Halfords and bought one and installed it and it worked although it doesnt work with the ignition and i have to manually turn the radio on and off which does not bother me at all but after i Installed it the rear speakers weren't working, so back online I go and someone said I actually needed the PC9-410 adaptor because it was a bose system and had amplified rear speakers! So off to halfless I went again and again installed it as instructed and again the rear speakers are not working! I'm at a complete lose as to how to get them working, and in all honesty I have no idea if it is a bose system or not! Some people said I should have a amp in the boot but I can't find it or anything to tell me if it is or not!? I just want my rear speakers to work! Haha, if anyone can help or has any advise it would be extremely welcome! Thanks in advanced, Duncan.