Let's put everyone's knowledge together for some of the more frequently asked questions here for E39's so when newbs come up, most of the questions they need answering would be found in one area... plus, it reduces the repetition of the same question over and over again and again and again and again.
please understand that this is focused on 540's. those with 525's, 528's, 530's and M5's, please feel free to let us know what you know!
and i'll begin with.......