After comparing schematics and wiring connections, here are the necessary info for the upgrade. I'm not saying (yet) that it can be done. I'm saying here are the bullet points: (I will update my post regardless of a successful upgrade or not)
. The connectors for US Leaf are E26 (L) and E45(R), both for halogen and HID.
. The former has 6 wires, the latter has 8 wires (i.e. 2 missing wires per headlight)
. Two of the missing connections require 10A
. The other two are to the Combination Meter
. Schematics and connections here:
https://imgur.com/a/LbR1MFJ