www.dubsinthebuff.com is a great local forum.
www.vwvortex.com has a lot of archived information, but may God be with you if you try to make a new thread.
You’ve got room for a double din head unit in your dash without any cutting. You just lose that little pocket above the stock HU. According to crutchfield you’ve got about 6 1/2 inches of depth to work with. IIRC there wasn’t a whole lot of room back there for shoving wires either, but it’s been 3 years since I had the radio out of the MKIV that I used to have.