Really not too bad, Interesting using HLC at night, I do on my overview cams but not my Z12's for LPR.. might play with that, shouldnt really need it with 1/1000 or 1/2000 exposure.
Plenty of old and damaged plates out there, I see about 20% or so. Hard to read even under ideal conditions at night. Sometimes the plate lights interfere with the IR, not sure I completely understand it, like on your last image.
One other thing, I think I have mine focused a litte tighter than you, may try a touch more zoom.?