[JettaRed]

To answer your question about going lean between shifts, I doubt that to be the case. If anything, the w/m would keep it richer than nothing at all. In other words, better than without w/m at all. I believe the DV dumps boost between shifts.

The white smoke at startup could be either water or oil, but because it lasted 10 minutes or so, it may be more likely water from the leaky head gasket. As you suspected on another forum, once the car warmed up and the head expanded against the block, the leak was sealed. However, something ended up blowing eventually.