Maybe I have a dirty mind (well, yes, I do), but the first part could be expanded out to “penis”, which would complete the set, as it were.
MGEMAY
A Rod Stewart fan, I’m guessing.
OM MAREN – no idea.
YESITSME --no apostrophe.
HIGH TAX --no doubt.
The last on a NY state plate.
SLRPWRD In NY. Did not look like a solar powered car. I think it was a prius.
In navalese, gundecking.
LDYRLTR No signage indicating her name was which is unusual for a Realtor. Perhaps she’s retired.
Decent bet they have solar panels on their roof at home. And the car is indeed mostly solar powered, albeit indirectly, when they charge it at home.
IMSNUPI There were a couple Peanuts’ Snoopy stickers to clarify it.
At least it wasn’t IMSNUKI. Worse yet on an NJ plate. 
STIPENE First initial, middle name of the director of the museum where I volunteer.
KDUNCAN Obvious name
D1SCUS ASU ‘fork’ plate. Likely a track and field enthusiast or maybe a fan of Disqus and the good one were already taken.
I saw several while out running errands today:
TAKSHVI on and Acura crossover. Not sure what it means, but it was parked outside an international grocery store if that is possibly a clue (They mostly sell Asian foods, but also some Middle Eastern, Indian, and Hispanic foods).
PITTSPA on a Ford Escape. I’m slightly embarrassed to admit I initially parsed it as “pit spa” before it clicked that it’s actually “Pitts, PA” as in Pittsburgh.
HARTGE 5 on a BMW 3-Series. “Heritage”? (Although the 5 might indicate a 5-Series in case I misidentified the car. Looked like the smaller 3-Series to me, though).
CHRRGD3 on a Tesla Model 3. “Charged 3”.
And what I’m pretty sure was SIX7LFE, although I didn’t get a good look at is as was passing me going the other direction. But if I got that right, then I assume “6-7 life”. Really? Someone got a custom plate based on that 6-7 meme that’s already pretty much over as far as I know.
MELLOW on a pale yellow convertible. (might actually have been YELLOW, I didn’t get a real good look across two lanes of traffic)
CHAAARG (Not 100% sure on the number of A’s, figure they put as many as fit)
WADE E. (Might be a name, might be someone associated with Indiana University).
GOSPD (another convertible) (Go Speed?)
NONAJO-- I figure it’s a form of Grandma Jo
RATED-E for everyone, I presume?
Three that I can’t figure out, all on ordinary looking cars:
PASCLOCK
NOGD4U no good for you? No God for you?
JP4U, not on a Jeep
Two legible ones:
VEG4N
MAD DOG on an older Honda Odyssey minivan. However my nephew took his dad’s Odyssey drag racing and beat a sports car --it does have 6 cyliders and good pickup
DIETRYNG
and
GODCNTRY
in the same supermarket parking lot–one leaving, the other entering.
A couple of late model Honda Civic hatchbacks on the freeway today:
FUJIN93 Camera related? Bicycle related? Or climbed Mt. Fuji 33 years ago?
RADCVIC On a blacked out Civic with a HUGE wing on the hatch. Funny angle of attack and big winglets at the ends, top and bottom. I’m guessing it adds a huge amount of aerodynamic drag without producing much, if any, useful downforce. But what’s a few miles per gallon penalty if it means you can look cool? 
TOYRUN on a Toyota 4Runner.
Pomelo Yellow two tone VW ID.Buzz with HYVIZ
LAKR55 on some SUV. I’m guessing that’s a reference to the Lakers, and 55 is a specific player’s number. But I’m not much of a sports fan, so I don’t know who that would be.
SLTHBUS on a 4Runner with a roof rack, like it might actually get used for backcountry camping or similar. Actually maybe it was a roof tent. But anyway, my first thought was “Slytherin bus”, like from Harry Potter. Then I thought “south bus” was probably more likely. Or “South Lake Tahoe something bus”, since that is near here and would be a nice place for camping.
No one of significance wore 55 for the Lakers, and they won the NBA championship in 54 but not 55.
Come to think of it, the 5s probably just represent S’s, and it’s just “Lakers”, because all the more logical spellings were taken.
Saw BARNLY on the way to work and DJOU on the way home.