I ran the Mog with the fuel cap released today, exactly the same as before, longish run then stalled, short runs after re-starting. The car is essentially still under warranty, and some warranty issues will be looked at when she goes back to MMC, slightly early because of this specific issue. Once this is sorted I'll look at the "B58 GEN 2 PCV Delete Kit".
I'd have to check compatibility, but this looks to be the one to go for:
B58 Gen 2 PCV Delete Kit
