UND2KK1 — baffling. Maybe University of Notre Dame, 2001? Yes that would be 2K1 but maybe that was already taken.
HUY MEC with a shield logo that looked military, but I didn’t recognize it. It might be Army. So maybe MEC = mechanized? When I see Huy, I think possibly Hue, in central Vietnam. A guess.
MADDIX. This reminded me that when I was a kid I used to watch the TV series, Mannix.
In a military context …
… Huey helicopter. AKA the Bell UH-1 Iroquois - Wikipedia.
The owner may have been a helicopter repairman. Or a “flight mechanic” AKA door gunner.
I do have friends with strong connections both to Colorado and to the Finger Lakes, often lately abbreviated as FLX. I don’t think they go in for vanity plates; but maybe someone with similar connections does.
On a Jeep with a “thin blue line” flag sticker and several eagles with stars and stripes wings: PROTACOL. Whether or not the misspelling was deliberate, I’ve no idea what it might mean.
Driver is fluent in over six million forms of communication. 
I’d sooner bet they’re wacko about the Protocols of Zion. But your idea is more fun.
I had to detour around my normal detour to and from work today- the road I would normally take to avoid the construction was closed this morning due to a crash and still closed this afternoon. My normal 10-minute-ish commute took over a half hour both ways. And I only got two meh plates out of it GOMEZ6 and L WHITE
Aah yes, that’s likely it.
SON SHY9. Sunshine!
MAX PWR1
KW POWR on a Tesla.
I thought I was going to go my entire commute home without seeing any, but finally, I spotted one:
GCGREGG – I assume the driver’s name is Greg, but what is GC? Initials? Or an abbreviation I’m unfamiliar with? It was on a big F250 with the FX4 Off-Road Package according to the decal on the side of the bed, in case that has anything to do with it. (As an aside, it was clean and shiny and looked like it’s never been off road in its life).
I did also spot 7TEN100, which is a regular series plate in California, but kind of an interesting one. I suppose “seven ten” could be a bowling reference, or a reference to the old Datsun 710 (But it was on a Camry), but I am 99.99% sure it’s just a normal series plate. But that begs the question, is there any rule against requesting something that fits the standard series pattern as a personalized plate? Like there’s been a lot of talk about how California’s current series is going to run out some time this year, and who’s going to get the last plate of the series. But could one just request 9ZZZ999 as a custom plate and get it before it gets issued to a random person?
Each state has different rules on that. You’d have to check about CA specifically.
Fun coincidence: in that very same vein, tonight I encountered BXPX20. On a FL standard plate, but not with the standard spacing. So clearly a custom plate. In FL (and I expect everywhere) spaces aren’t significant for the meaning of the plate, so ABC123, A⎵B⎵C123 and ABC⎵⎵123 are all considered the same sequence. Once one is issued the others are blocked.
It was about 10-15 years ago that the standard sequence pattern here was ABC⎵⎵D12. I had two plates like that.
So what might, might BXPX20 mean? My theory is someone who worked for the military Base Exchange / Post Exchange AKA retail store network (Army & Air Force Exchange Service - Wikipedia) and retired after 20 years of federal service there.
Or not and it’s just a regular plate. But that doesn’t explain the non-standard spacing.
ADVENTYR on a big SUV.
PRTYNNK on a black car. My guess: Pretty in Ink
I’m pretty sure one cannot.
A lady driving an SUV with LVMIDGS. She loves her dogs.
JONECAR. Johnny, or Joanie.
MAX PWR1
MYRAVBO on a RAV4. My guess is they wanted “My RAV, bro,” but there wasn’t enough space. But it makes me think “My RAV B.O.”
Also POPZTOP on a Prius, which I may have mentioned before because it’s in my neighbor’s driveway and I’m sure I’ve seen it before. I’m not sure what that has to do with a Prius, it would make more sense on a convertible.
Today in California, I saw NAAARFF. Not especially clever, but it reminds me of one of my favorite cartoon series, Pinky and the Brain. They had some kind of doll-figure attached to the trunk, but it wasn’t Pinky, it looked more like a version of the Grinch – I was off to one side and driving, so I wasn’t able to stare at it for very long.
HANGE Z on a Nissan Z. The Z is obvious, but what does HANGE mean? (There is a possibility that I’m remembering it wrong, or I read it wrong since I was on foot and I only got a short look at it as it drove past.)
I saw either 420RK or 42ORK today. It’s really hard to tell an O from a zero on Indiana plates. It had to be something custom, as far as I can tell the minimum is six characters on a normal plate. You used to be able to pay extra for a low numbered plate but I don’t know if that’s a thing anymore.
Not in California. Decades ago I read of a guy who tried to order ZZZ 999 and was turned down flat.
Did they ever issue NNNN AAA NNN plates? They could start the cycle again with 1000 AAA 000 and that would last quite a while.