The second circled item (i.e. the one in the middle) could be a couple of things. It could be a stud that the under-manifold harness casing bolts to or one that the dipstick bolts to. I'm not certain, but it's likely one of those two things. Open up your Bentley and have a browse... or, if you're really adventurous, remove the intake manifold on your E46 and have a peek.
This should be a really interesting thread. Good luck!