Lots to update on.
The "exhaust smell" I thought was coming from a defective turbocharger was actually from my goddamn stupid ECS tuning catch can dripping oil from the rear fitting on the back of the cylinder head, which dripped on to the back of the motor/turbo causing the smell. Thank GOD I discovered that before I pulled the turbo again. New rear fitting on the way.
I finally got around to installing my APR OPS kit. I did a full write up of it here:
https://www.golfmk6.com/forums/showthread.php?t=117605
I heeded some advice from Hyde to reconnect the front PCV hose. Since then, there has been substantially less (if any) oil in my catch can, which would typically be filled to the brim after 1 autocross event. Very promising results so far, will hopefully see less oil in my intercooler as a result.
Next update, I got my hands on a Kenwood DNX516ABS head unit. You may remember this from Paddie McGrath's car "Project GTI" - it's the exact same one. It was only available in the UK/Europe, but it was purchased from a German eBay vendor and the seller already went through the trouble of obtaining US maps on an SD card. I just need to get the firmware updated. Unlike other aftermarket radios that look like poop, this radio looks absolutely OEM, and integrates with the MDF like a VW radio would.
Finally, enjoyed a fun (but cold) day at Thompson for CART's last event of the season:
https://youtu.be/5KKI7hW-PMg
Stability control was kicking in like CRAZY. Was getting pretty pissed, so figuring out how to deactivate that through VAGCOM is going towards the top of my list.
More updates coming soon!