IR LED illumination of your license plate bulbs might help slightly at night.

[link to www.wired.com]

But of course it's not to violate the law but just to light up your plates. It's just that they never said what color you could use and while you should use a mix of white LEDS so the officer can make out your tag CMOS and CCD based tech cameras are another story.

DISCLAIMER: No legal advice is intended.