That is correct, there is a solenoid which operates and moves the shield out of the way giving the full xenon lamp unshielded for full beam!
No, I have 4 x Bi-Xenon projectors, as in all 4 on for lo and hi beam!
*** Ignore the sidelights, that was just a trial fit! ***
I chose the Audi units because they are Bi-Xenon and because they are made by Hella and therefore fit most headlight units, the BMW ones don't fit in the R33 headlight units (Bi-Xenons that is). As for the Honda units, I don't know to be honest, it wasn't an option available to me at the time.