I just installed a Pioneer 4 channel amp to my Golf 90TSI, I tapped into the speaker wire down under the trim of the door sills I didn't use RCA's. With a lot of mucking around I got battery power but to find an accessory feed for the amps remote on was and still is a challenge. I ended up using a piggy back fuse and used the Infotainment fuse on the fuse box I would like to know if there is a better option . The Amp makes a huge difference to the sound of the factory head unit but I have one problem. When I turn off the ignition and get out of the car then shut the door after a few seconds I hear a pretty loud thump through the speakers, the same thing happens when I first unlock and open the door, after a few seconds I hear a thump through the speakers even though the keys aren't in the ignition. I'm at lost at what's causing this thump through the speakers if I can't solve it I will have to remove the Amp. Any help appreciated.