Just bought a new-to-me 2001 Passat 1.8T. Was told by the P/O that it had a battery drain that would kill the battery in a few days. Well I'm pretty sure I found it. The car had an aftermarket head unit installed. I noticed that after I turned the car off and took the key out, there would be a faint static/white noise coming from the speakers even though it appeared the radio was off (couldn't make it do anything). I'm thinking this sound is my battery drain. Figured it was the crappy head unit so I ordered a cheesy $30 one from Amazon to replace it with. Installed the new one yesterday and amid other problems with it, the white noise when the car's off is still there! Could be the crappy new head unit so I'm getting a refund for it but they dont want it back haha. I now have a decent one on order. I'm pretty sure I wired it in correctly, I put the yellow memory wire to the stock harness and I have the radio power coming from the 75X bolt that comes from the ignition. I noticed that when I unplugged the connector that has the yellow battery wire going to the head unit, the sound goes away so something might be screwy with that. Anyone ever had this problem before? I've looked into this as much as I can and haven't come up with much. I've seen it could be a ground, bad amp (do these cars have amps for the door speakers?), or a bad head unit. I think I'll run the wire to a screw on the frame for a new ground and see if that helps me any. I really want to have a working radio in my car so any help would be appreciated!