The Model ☰ vehicles seen in other instances of
'In the Wild' since the reveal do have actual license plates, though they are of the
'MFG' variety. The cars will have VINs though... Check out this site:
VIN Decoder | TeslaTap
The 12th position in a VIN,
'Build Phase Code', shows what would cover these early cars...
A = Alpha Prototype
B = Beta Prototype
E = Evaluation Prototype, Roadster
F = Founder Series Vehicle
M = Mule, Roadster, early prototype
P = Production Vehicle
R = Release Candidate Vehicle
S = Signature Series Vehicle
V = Validation Prototype, Roadster
So, Alpha, Beta, Evaluation, Validation, and Release Candidate vehicles are the sorts of cars that are
'Development' vehicles, and don't apply toward the IRS total even though operated in the US. I believe only the Production vehicles count toward the 200,000 total that initiates the phaseout of Federal Tax Credits.