It could be for an LLB, which is for a Bachelor in Law, an undergraduate degree. In the US it has become obsolete, replaced by JD, for juris doctor, the terminal law degree, as they say. It is still used in Britain and India. It pops up in my British murder mysteries occasionally. Whether some Miamisn aspired to the law and acquired a British or Indian prerequisite is far beyond my ken.
The plate was LBB not LLB. But good guess.
When I saw it I thought of LLM, the Master of Laws degree and at first thought just what you did, that the plate meant the bachelor version of that. A second look showed the plate had double-B, not double-L.
Thanks for playing though! Carrol Merrill will have a consolation prize waiting back at your seat. 
Today I saw DLSTURF on a shiny Range Rover. At first I thought “DL sturf”, with “sturf” being an alternative spelling for “stuff”.
Then I recognized “turf” and thought it might be “DLS turf” or “DL’s turf” for some sort of landscaping biz. Turns out I was right:
The website doesn’t have a physical address, but the phone number is one of our local area codes, so decent bet it’s them.
Saw BOYBY3 this morning.
Pretty pic. What might it mean?
Wheelchair-bound South Park character named Timmy who says little more than his own name.
On the way to work this morning: WATCH AU. A gold trader or someone recently retired?
I had a curiously one-dimensional haul in the parking lot at breakfast this morning.
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RAP⎵1 on the 5-character marine mammal booster plate.
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MSS⎵1 neatly centered on the standard FL plate.
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KROLE1⎵⎵ left justified on the the standard FL plate.
Presumably just names and initials. Pretty boring. Boring cars too.
On the way home today, less clever for the message than the spelling: MY T35LA (on, yes, a Tesla SUV).
HAIR2DY4
The windows were too dirty to catch a good luck at the driver and their hair.
On a MA plate - SOXRUL, pretty self-explanatory.
On a NH plate - THEHECK, which frankly, I’m surprised that was allowed.
L8KDAYS. I assume L8 = “late”, and DAYS is self explanatory, but I don’t get the K. Unless I’m wrong about the first part, and L8K is a word? Maybe L8K = “lake”, so “lake days”?
IMO “lake days” is it.
I think Lake Days as well, but you know MOMC4R URLOUD! Actually the mom car wasn’t loud, but I am sure being an ICE car it is when compared to the EV with the URLOUD plate.
//i\\
Decided I needed something different to wear to a Christmas party I have to go to and saw MACY in the Kohl’s parking lot. Would have been funnier if I was at Macy’s but what can you do?
Then on the way home I saw a Dodge Charger being driven by a younger guy… with a license plate that read POOKY. 
I just saw a family wagon with a 5-character child abuse booster plate that said AGIOS. I suppose that’s a close-enough spelling for “Adios” that was already taken.
This morning on a silver Tesla (model X, IIRC): QKCILVR
YES, spelled that way.
Someone really wanted a “Quicksilver” plate, and had to go well down their list of increasingly-tortured spellings to get it.
I know what you mean given the context, but these days when I see “ICE car” I think of something else.