Grrrr... Been happening to me again recently. Feels like it happens every single cold day after I drop off my kid at daycare and start the car. It seems to happen far more often when on a flat or slight decline. A couple of times now it popped so far out of gear that it took a second or two before the car would even move after the initial jolt.
I don't recall where now, but I read somewhere that someone got their turbo swapped by the dealer and it resolved the issue. What if the entire process is actually happening as a fail safe because it thinks the car is about to stall? My is20 is definitely leaking some oil at the bearing. No shaft play yet, but I'm willing to bet it will let go any month now...
The other day it actually got so frustrating that I spent a few hours debating on selling it for a new manual M3. Too bad they're so hideous on the front end, but I'm still considering it... I just have so much to unmod on the car before selling it