I just bought a 2011 GTI and I got the one with navigation im going to be putting in a 2800 watt 15 sub. I was wondering if the factory radio had all the necessary connections, I put some 10's in my Tacoma and it was pretty easy was wondering how involved it is in this vehicle. Any advice would be great.
For the stereo, you can take the speaker wires and directly wire them to RCA connectors and feed them to the line in for the amp. Do a search, they are line level. That's what I did, I took the rear line speaker wires (front ones were affected by crossovers) and wired them to the amp.
On vagcom I changed speakers from VW to Skoda (not dynaudio) and 4 passive speakers to none.
The sound is flatter. It feels like the high range boost is gone now and much more balanced. I like it now on my rcd510
Check out my stealth subwoofer. I made a 3'x3'x4" enclosure using 3/4 MDF and gutted the storage compartment in the cargo area. Placed it right above the spare tire. The magnet of the 15" fosgate sits into the well of the spare. Hits hard, sounds clean, and is stealth. No loss of cargo space!
http://forums.tdiclub.com/showpost.php?p=3401591&postcount=32
BTW, this is for a JSW [golf variant, not the smaller golf]