Joe, hope it is alright to Pm this question rather than starting to or adding to any of the many existent oil debate threads.
I recently hit 10k miles in my 08 spec b and decided to switch to synthetic. In most previous cars I've run mobil 1 0w40 without issue. I was unable to find any for this change and settled for mobil 1 5w30.
The guy helping me tune my car has highly recommended I swap out the mobil 1 for either Penzoil Platinum, Rotella or Castrol syntec. Today, I actually mis-shifted a 3rd to 4th and hit 2nd gear. I briefly over-revved my engine to 9100 rpms. Hopefully I didn't break anything, but I'm going to do and oil and filter swap before driving it further.
I'd really love to go with a 5w40 Rotella, and probably will in the summer, but I think it gets too cold here (Western NY). It's been in the single digits already a few times this year.
I know that you're fairly up to date on your oil knowledge, and are the type that can "feel" the difference in the car between various oils. What are you currently running in the LGT? How about the Si? Have you tried and ruled out any brands as of yet? Penzoil Platinum, and Castrol Syntec seem to be the only readily available stocked synthetics in my neighborhood other than mobil 1.