we are all starting to arrive at a consensus that if the gas makes it all the way up from the HPFP's rubber hoses, to the tank vent valves and then, into your intake manifold, something bad is up with the HPFPs. When the engine is cold, I would open the hose on top of each HPFP and drain gas from there. (well, and at the tank vent quick releases, too) Drive, check the next day when cold to see if you are still generating gas from the tops of the HPFPs--we believe it's coming from there, so there's probably some there to see in the morning. That would be a cause to believe your HPFPs are starting to fail and leak into the vent tubing.
For instance. The wreck had about a quarter shot-glass of gas at each HPFP when I first got it. Since then, I have started and ran the motor several times for a total of a few hours. I have seen no more gasoline gather at the HPFPs when I check the hoses when the engine is cold. My thinking is: 1] car upside down, maybe that's how it got there, as we discussed. 2] not sure, but can gas condense? could 50K miles of gas vapor result in some condensation? The HPFPs are certainly at the lowest point in the engine bay for the vent hoses. If there were some condensation, it would roll down to the HPFPs and sit there.
One member, Gadget, had hesitation, bad engine behavior, and had gas in his Tank vent Valves, and the valves and hoses replaced and drove a few 1000s miles and BMW told him there was no more gas forming in the hoses right on the HPFPs. Not sure how his gas got into his tank vent valves in the first place, but that is what BMW told him, and apparently, his car ran great--until it got wrecked unfortunately. So that case is interesting.
The more of us who report this issue, the better to nail it down.